1994 FIAT PUNTO check engine light

I
8*4 Driveshafts
3.3 Using pair of circlip pliers, expand the circlip that holds the driveshaft in place
Turbo diesel models 4 Mark the relationship between the joint and the driveshaft using a scriber or a dab of paint. Attach a slide hammer to the dnveshaft nut thread. 5 Draw the joint off the driveshaft using the slide hammer, Use just enough effort to overcome the tension of the internal circlip.
Inboard CV joint removal All models except turbo dieseis 6 Al the inboard end of the driveshaft. use a hammer and centre punch to mark the relationship between Ihe shaft and |olnt. Remove the circlip with a pair of circlip pliers, then using a three-legged puller if required, draw Ihe tripod joint off the end of the driveshaft. Ensure that the legs of Ihe puller bear upon the cast centre section of the joint, not the roller beanngs (see illustration) Turbo diesel models 7 Al the inboard end of Ihe driveshaft. use a hammer and centre punch lo mark the relationship between the shaft and joint. Remove the circlip with a pair of circlip pliers, then carefully slide the CV joint from the end ot the shaft. Take great care to prevenl the
cage and bail bearings from falling out • secure the joint components together with wire or a nylon cable-tie. 8 Remove the washer then slide the flange from the end of the shaft.
Inspection 9 Slide both rubber gaiters off the driveshaft and discard them: It is recommended that new ones are fitted on reassembly as a matter of course. Recover the flexible washers (where fitted), making a note of their fitted positions, to aid correct refitting later. 10 Thoroughly clean the driveshaft splines, and CV joint components with paraffin or a suitable solvent, taking care not to destroy any alignment marks made during removal. 11 Examine Ihe CV joint components for wear and damage: in particular, check the balls and corresponding grooves for pitting and corrosion. If evidence of wear Is visible, then the joint must be renewed. Note that if the outboard CV joint Is to be renewed on turbo diesel models, it must be matched to the driveshaft using the colour-coded paint markings. 12 Where applicable, examine the tripod joint components for wear. Check thai the three rollers are free lo rotate without resistance and are not worn, damaged or corroded. The rollers are supported by arrays of needle bearings: wear or damage will show up as play In the rollers and/or roughness in rotation. If wear is discovered, the tnpod joint must be renewed. 13 Fit a new rubber gaiter (and where applicable, flexible washer) to the inboard end of the driveshaft and secure it In place on the shaft with a clip (see illustration).
Inboard CV joint - refitting
All models except turbo dieseis 14 Using Ihe alignment marks made during removal, fit the tripod joint onto the splines of the driveshaft. Tap It Into position using a soft faced mallet. To ensure that the tripod Joint rollers and driveshaft splines are not damaged, use a socket with an internal diameter slightly larger than I hat of the driveshafl as a drift. Refit the circlip. 15 Slide the gaiter over tho tripod joint and pack the gaiter with grease from the service kit.
3.6 Draw the tripod joint off the end of the driveshaft 3.13 FH s new rubber gaiter to the inboard end of the driveshaft and secure It in place with a clip
Caution: Do not allow grease to come
into
contact with vehicles paintwork, es discolouring may rasutt. Turbo diesel models 16 Slide the flange and washer onto the end of the shaft, then fit the joint Into position on the driveshaft splines, using the alignment marks made during removal. Fit the circlip. ' 17 Pack the gaiter with grease from His service kit, then slide the gaiter over the joint. Briefly lift the lip of the gaiter to expel ail the air from the joint, then secure the gaiter over the joint with a new clip. Caution: Do not allow grease to come
Into
contact with the vehicle's paintwork, as discolouring may result.
Outboard CV joint - refitting 18 Fit a new rubber gaiter to the outboard end of the driveshaft and secure it place with a dp, 19 Pack the CV joint with grease from Ihe service kit, pushing It into the ball grooves and expelling any air that may be trapped underneath. 20 Lubricate the splines of the drive shaft with a smear of grease, then whilst splaying the circlip open with a pair ot circlip pile*, insert the driveshaft into CV joint, observing the alignment marks made during removal. Note: On turbo diesel models, the circlip snaps into the CV Joint groove as Ifte driveshaft is inserted - no circlip pliers are required. Ensure that the circlip snaps securely Into place: pull on the shaft to check that it is held firmly In position. 21 Pack additional grease Into the joint to displace any air pockets, then slide the rubber gaiter over the joint. Briefly lift the lip ol the gaiter to expel all the air from Ihe joint, then secure it In place with a clip. 22 Refit the driveshaft (see Section 2).
4 Intermediate driveshaft - % removal and refitting J;
Note 1: This procedure applies only to turbo diesel engined models. Note 2: The intermediate shaft and
bearing
are not available as separate spares and cac only be renewed as a comptefe assembly.
Removal 1 Firmly apply the handbrake, then jack up the front of Ihe car and support It securely
on
axle stands (see Jacking and vehicle support). Remove the appropriate roadwheei(s). 2 Unbolt the inboard end of the right*hand driveshaft from the intermediate shaft
flange, as
described In Section 2. Suspend the dis-connected end of the driveshaft from a conven-ient point on the subframe, using wire or a cable-tie. to avoid straining the joint and gaiter. 3 Drain the oil from the transmission, with reference to Chapter 1B.

9*10 Braking system
10.6 Disconnect the relevant handbrake inner cable (arrowed) from the draw bar 6 Working inside ihe vehicle, remove Ihe screws and lift off the handbrake lever trim panel (refer to Section 9 for more detail). At the base of the handbrake lever, full/ slacken off the handbrake adjusting screw and locknut, to remove oil tension from the cable draw bar, then disconnect the relevant handbrake inner cable from the cable draw bar (see illustration) 7 Release the cable grommet from tho floor-pan, then withdraw the cable from the vehicle.
Refitting 8 Refitting Is a reversal of removal, bearing in mind the following points: a) Ensure that the cables are securely fastened In the clips on the floorpan beetshield and lower suspension a/m. b) On completion, check the handbrake adiustment, as described in Section 9.
11 Hydraulic system -bleeding

A


Warning: Hydraulic fluid is poisonous; wash off immediately and thoroughly In the case ot skin contact, and seek immediate medical advice if any fluid is swallowed, or gets into the eyes. Certain types of hydraulic fluid are Inflammable, and may ignite when allowed into contact with hot components. When servicing any hydraulic system, it Is safest to assume that the fluid IS inflammable, and to take precautions
11.17 Bleeding a rear brake line
against the risk of fire as though it is petrol that Is being handled. Hydraulic fluid is also an effective paint stripper, and will attack plastics; If any is spilt, It should be washed off immediately, using copious quantities of fresh water. Finally, it Is hygroscopic (it absorbs moisture from the air) • old fluid may be contaminated and unfit tor further use. Whan topping-up or renewing the fluid, always use the recommended type, and ensure that It comes from a freshly-opened sealed container.
General 1 The correct operation of any hydraulic system is only possible after removing all air from the components and circuit; and this Is achieved by bleeding the syslem. 2 During the bleeding procedure, add only clean, unused hydraulic fluid of the recommended type; never re-use fluid that has already been bled from the system. Ensure that sufficient fluid is available before starting work. 3 If there is any possibility of incorrect fluid being already in the system, the brake com-ponents and circuit must be Flushed completely with uncontamlnated, correct fluid, and new seals should be fitted throughout the system. 4 If hydraulic fluid has been lost from the system, or air has ontered because of a leak, ensure that the fault is cured before proceeding further. 5 Park Ihe vehicle on level ground, switch off the engine and select first or reverse gear (or P), then chock the wheels and release the handbrake. 6 Cheek that all pipes and hoses are secure, unions tight and bleed screws closed. Remove Ihe dust caps (whore applicable), and clean any dirt from around the bleed screws. 7 Unscrew the master cylinder reservoir cap, and top Ihe master cylinder reservoir up to the MAX level line; refit the cap loosely. Rememoer to maintain the fluid level at least above the MIN level line throughout the procedure, otherwise there is a risk of further air entering the syslem. 8 There are a number of one-man. do-It-yourself brake bleeding kits currently available from motor accessory shops. It is recommended that one of these kits is used whenever possible, as they greatly simplify the bleeding operation, and also reduce the risk of expelled air and fluid being drawn back into the system. If such a kit is not available, the basic (two-man) method must be used, which is described in detail below. 9 If a kit Is to be used, prepare the vehicle as described previously, and follow the kit manufacturer's instructions, as Ihe procedure may vary slightly according to the type being used; generally, they are as outlined below in the relevant sub-section. 10 Whichever method is used, the same sequence must be followed (paragraphs 11 and 12) to ensure Ihe removal of all air from the system.
Bleeding sequence 11 If Ihe system has been only
partial!?
disconnected, and suitable precautions wwe taken to minimise fluid loss, it should be necessary to bteod only that part of the system (le the primary or secondary circuit). 12 If the complete system Is to be bled, then It should be done working in the following sequence: a) Left-hand rear wheel b) Right-hand front wheel. c) Right-hand rear wheel. d) Left-hand front wheel. Note: When bleeding the rear brakes
on a
vehicle ritled with load proportioning valves: i the rear of the vehicle has been jacked
up to
allow access to ihe brake wheel cylinder,
tha
rear suspension must be compressed
(eg
raising the beam axle with a trolley
jack) so
that the load proportioning valves
remain open
throughout the bleeding process.
Bleeding -basic (two~man) method 13 Collect a clean glass jar, a suitable length of plastic or rubber tubing which Is a light fit over the bleed screw, end a ring spanner lo
Rt
the screw. The help of an assistant will also tie required. 14 Remove the dust cap from the first screw In the sequence if not already done. Fit a suitable spanner and tube to the screw, place the other end of Ihe tube In the jar. and
pour in
sufficient fluid to cover the end of the tube. 15 Ensure that the master cylinder reservoir fluid level is maintained at least above the
MIN
level line throughout the procedure. 16 Have the assistant fully depress the brefce pedal several times to build up pressure, then maintain it on the final downstroke. 17 While pedal pressure is maintained, unscrew ihe bleed screw (approximately one turn) and allow the compressed fluid and orto flow into the
Jar,
The assistant should maintah pedal pressure, following the pedal down to the floor if necessary, and should not rrtaase Ihe pedal until instructed to do so. When ihe flow stops, tighten the bleed screw again, have the assistant retease the pedal sfowty, and recheck the reservoir fluid level (see Illustration). 18 Repeat Ihe steps given in paragraphs 16 end 17 until the fluid emerging from the bled screw is free from air bubbles. If Ihe master cylinder has been drained and refilled,
and
at Is being bled from the first screw In the sequence, allow approximately five seconds between cycles for the master cylinder passages to refill. 19 When no more air bubbles appear, tighter, the bleed screw securely, remove Ihe tube arc spanner, and refit the dust cap (where applicable). Do not overtighten the bleed sew. 20 Repeat the procedure on tho remaining screws In the sequence, until ail air is removed from the system, and the brake pedal feels firm again.

Braking system 9®11
Bleeding • using a one-way valve kit 21 As their name implies, these kits consist ol a length of tubing with a one-way valve Fitted, to prevent expelled air and fluid being drawn back into the system; some kits include a translucent container, which can be positioned so that the air bubbles can be more easily seen flowing from the end of the tube. 22 The kit is connected to the bleed screw, which is then opened. The user returns to the driver's seat, depresses the brake pedal with a smooth, steady stroke, and stowty releases it; this is repeated until the expelled fluid is clear of air bubbles. 23 Note that these kits simplify work so much that It is easy lo forget the master cylinder reservoir fluid level; ensure that this Is maintained at least above the MIN level line at all times.
Bleeding -using a pressure-bleeding kit 24 These kits are usually operated by the reservoir of pressurised air contained in the spare tyre. However, note that it will probably be necessary to reduce the pressure lo a lower level than normal; refer to the instructions supplied with the kit. 2$ By connecting a pressurised, fluid-filled container to the master cylinder reservoir, bleeding can be carried out simply by opening each screw In turn (in the specified sequence), and allowing the fluid to flow out until no more air bubbles can be seen in the expelled fluid. 28 This method has the advantage that the large reservoir of fluid provides an additional safeguard against air being drawn into the system during bleeding. 27 Pressure-bleeding is particularly effective when bleeding 'difficult' systems, or when bleeding the complete system at the time of routine fluid renewal.
All methods 28 When bleeding is complete, and firm pedal feel is restored, wash off any split fluid, lighten the bleed screws securely, and refit their dust caps (where applicable). 29 Check the hydraulic fluid level in the master cylinder reservoir, and top-up if necessary. 30 Discard any hydraulic fluid thai has been Wed from the system; it will not be fit for re-use. 91 Check the feel of the brake pedal. If it feels at all spongy, air must still be present in Vie system, and further bleeding is required. Failure to bleed satisfactorily after a reasonable repetition of the bleeding procedure may be due to worn master cylinder seals.
12 Master cylinder- % removal
and
refitting SK

A


Warning: 8efore starting work, refer to the warning at the beginning of Section 11 concerning the dangers of hydraulic fluid.
Removal 1 Remove the master cylinder fluid reservoir cap, and syphon the hydraulic fluid from the reservoir. Note: Do not syphon the fluid by mouth, as It Is poisonous; use a syringe or an old poultry baster. Alternatively, open any convenient bleed screw In the system, and gently pump the brake pedal to expel (he fluid through a tube connected to the screw (see Section 11). Disconnect the wiring connector from the brake fiuld level sender unit. 2 Carefully prise the fiuld reservoir from the seals and release it from the top of the master cylinder. 3 Wipe clean Ihe area around the brake pipe unions on the side of the master cylinder, and place absorbent rags beneath the pipe unions to catch any surplus fluid. Make a note of the correct fitted positions of the unions, then unscrew the union nuts and carefully withdraw the pipes. Plug or tape over the pipe ends and master cylinder orifices, to minimise the loss of brake fluid, and to prevent the entry of dirt into the system. Wash off any spilt fluid immediately with cold wafer.
A 22.45 to 22.65 mm
Cut the finger tips from an old rubber glove end secure them over the open ends of the brake pipes with elastic bands • this wifi heip to minimise fluid lots and prevent the Ingress of contaminants.
4 Slacken and remove the nuts securing the master cylinder to the vacuum servo unit, then withdraw the unit from the engine compartment. 5 Where applicable, recover the seals from the rear of the master cylinder, and discard them; new items must be used on refitting. 8 With the master cylinder removed, check that the distance between the end of the vacuum servo unit pushrod and the master cylinder mating surface is as shown in the diagram. If necessary, the distance may be adjusted by turning the nut at the end of the servo unit pushrod (see illustration).
Refitting 7 Fit new rubber seals and then press the fluid reservoir into the ports at the top of the master cylinder 8 Remove all traces of dirt from the master cylinder and servo unit mating surfaces, and where applicable, fit a new seal between the master cylinder body and the servo. 9 Fit the master cylinder to the servo unit, ensuring that the servo unit pushrod enters the master cylinder bore centrally. Refit the
B Adjustment nut

Suspension and steering 10*11
13.11b ... and left-hand steering gear-to-subframe bolts
hooked onto the engine lifting eyelet on the cylinder head. Working underneath the vehicle, unbolt and remove the transmission-lo-subframe rear mounting bracket. 13 Position a trolley jack under the right hand skle of the subframe crossmember. Raise the jack to take the weight of the crossmember
and
the attached components. 14 With reference to Section 4, slacken and remove the two bolts that secure the suspension lower arm rear bush to the subframe. Slacken and withdraw the subframe-to-bodywork bolt, located adjacent to the rear of the suspension lower arm. Throad two flange head bolts of the same thread size, but approximately 25 mm longer into the vacated holes, then carefully lower
the
trolley jack and allow ihe subframe to rest on the heads of the temporary bolts (see (lustration), 15 Repeat the operations in paragraphs 13 end 14 at the left-hand side of the vehicle. On completion, the subframe should be resting at
&
height approximately 25 mm lower than normal. 16 The additional clearance will now permit the steering gear pinion to be lowered away from the bulkhead. When the end of the pinion has cleared Ihe aperture, manoeuvre the entire steering gear assembly through the *tiae?arch.
Refitting 17 Refitting is a reversal of removal, noting
the
following points: s) Remote the temporary bolts and refit the original length fixings.
13.14 Slacken and remove the subframe-to-bodywork bolts (arrowed)
b) Tighten all fixings to the specified torque settings. c) Refill the hydraulic system with the specified grade and quantity of power steering fluid (see Lubricants and fluids In Weekly checks), then thoroughly bleed the system as described in Section 15. d) On completion, have the front wheel alignment checked at the earliest oppor-tunity by a Flat dealer or a tyre specialist.
14 Steering gear rubber gaiters - renewal <
Note: New gaiter retaining clips should be used on refitting. 1 Remove the relevant track-rod end as described in Section 17. 2 If not already done, unscresv the track-rod end locknut from Ihe end of the track-rod. 3 Mark the correct fitted position of the gaiter on the track-rod, then release the gaiter securing clips. Slide the gailer from the steering gear, and off the end of the track-rod. 4 Thoroughly clean tho track-rod and the steering gear housing, usrng fine abrasive paper to polish off any corrosion, burrs or sharp edges, which might damage the new gaiter sealing lips on installation. Scrape off all the grease from the old gaiter, and apply it to the track-rod inner balljoint. (This assumes that grease has not been lost or contaminated as a result of damage to the old gaiter. Use fresh crease if In doubt.) 5 Carefully slide the new gaiter onto the track-rod. and locate it on the steering gear housing. Align the outer edge of the gaiter with the mark made on the track-rod prior to removal, then secure it in position with new retaining clips. 6 Screw the track-rod end locknut onto the end of the track-rod. 7 Refit the track-rod end as described in Section 17.
15 Power steering hydraulic system • bleeding ^
General 1 The following symptoms indicate that there is air present In the power steering hydraulic system: a) Generation of air bubbles in fluid reservoir. b) Clicking noises from power steering pump. c) Excessive buzzing or groaning from power steering pump. 2 Note that when the vehicle Is stationary, or while moving the steering wheel slowly, a hissing noise may be produced In the steering gear or the fluid pump. This noise is inherent in the system, and does not indicate any cause for concern.
Bleeding 3 Chock the rear wheels, apply the handbrake, then jack up the front of the vehicle and support securely on axle stands (see Jacking and vehicle support). 4 Check the fluid level in the power steering fluid reservoir (bear in mind that the vehicle will be tilted, so the level cannot be read accurately), and if necessary top-up to just above the relevant level mark. 5 Have an assistant tum the steering quickly from lock to lock, and observe tho fluid level, if the fluid level drops, add more fluid, and repeat the operation until the fluid level no longer drops. Failure to achieve this within a reasonable period may indicate a leak in the system. 6 Stan the engine and repeat the procedure described In the previous paragraph. 7 Once the fluid level has stabilised, and all air has been bled from the system, lower the vehicle to the ground.
16 Power steering pump - Sk removal and refitting ^
Removal 1 Drain as much fluid as possible from the power steering reservoir, using a pipette or an old poultry baster. 2 Remove the clip and disconnect the rubber fluid supply hose from the port on the top of the power steering pump. Be prepared for an amount of fluid loss • position a container underneath the port and pad the surrounding area with absorbent rags. 3 Slacken the union and disconnect the fluid delivery hose from the side of the power steering pump. Again, be prepared for an amount of fluid loss. 4 Unscrew tho clamp bolt and through-bolt at either end of the drivebelt guard, then detach Ihe guard from the power steering pump (see illustrations). 5 Partially unscresv the two power steering pump mounting bolts then rotate the pump towards the engine slightly, to release the tension from the belt. Carefully ease the drivebelt from the pump pulley.
16.4a Unscrew the clamp bolt...

Bodywork and fittings
11
*7
12.4 Adjusting the extension of the bonnet pin
12 Bonnet lock components - ^ removal and refitting H
Latch and release lever assembly
Removal 1 Secure the bonnet In the fully open position using the stay. Mark the relationship between the latch and the surface of the bonnet using a soft pencil or marker pen. 2 Slacken and unscrew the bolts, then lower the latch assembly away from the bonnot. Refitting 3 Refitting is a reversal of removal. Use the alignment markings made during removal to aid accurate refitting. Note that the mounting holes are slotted to allow adjustment if required. On completion, tighten the bolts securely. 4 The extension of the bonnet pin may be adjusted in necessary, by slackening the locknut and turning the pin with a flat-bladed screwdriver (see illustration).
Striker plate
Removal 5 Mark the relationship between the striker plate and the bodywork using a soft pencil or marker pen. The striker plate can then be removed by slackening and withdrawing the three securing bolts and unhooking the release cable from the operating lever. Refitting 6 Refitting is a reversal of removal. Use the alignment markings made during removal to aid accurate refitting. Note that the mounting holes are slotted to allow adjustment if required. On completion, tighten the bolts securely.
Suffers 7 If necessary, adjust the protrusion of the rubber buffers on the front crossmember, (located above each headlamp unit) by screwing them in or out as appropriate. When the rubber buffers are correctly adjusted, there should be just enough free movement to
14.3a Remove the screw .
allow the bonnet to be closed and locked easily, without using excessive force, but not enough to allow the bonnet to rattle when secured in the locked position.
13 Bonnet release cable -removal and refitting I
Removal 1 Secure the bonnet in the fully open position. With reference to Section 12, detach Ihe bonnet release cable from the striker plate operating lever. 2 Unscrew the cable clip from above the nght hand headlamp unit. 3 Working around the engine bay, extract the release cable from its securing clips. 4 In the drivers footweil, extracl Ihe fixings and lower the sound insulation panel (where fitted) away from the underside of the steering column/facia. 5 Push the bonnet release handle towards the bulkhead slightly, then free the release cable end fitting from its recess in the handle. Lift the cable inner up, pass the end fitting through the larger hole and withdraw it from the handle. Extract the release cable outer from the mounting bracket by carefully pulling down on the plastic collar. 6 Release the cable from the remaining clips under the facia, then carefully pull the entire cable through the bulkhead grommet Info the engine bay.
14.3b ... then prise out the door grab handle moulding
Refitting 7 Refit the cable by reversing the removal process. On completion, close the bonnet to check that it locks securely, then check the operation of tho release mechanism. If adjustment is required, this can be achieved by repositioning the slotted plastic collar fitted to the cable outer sheath, in the mounting lug on the underside of the striker plate.
14 Door inner trim panel -removal and refitting I
Removal Note: This section describes the removal of the front door trim panel; the procedure for removing the rear door trim panel is essentially the same, 1 Disconnect the battery negative terminal (refer to Disconnecting the battery in the Reference Section of this manual). 2 With reference to Section 17. remove the trim panel from the rear of the door mirror fixings. 3 Lift off the caps and remove the screw, then prise out the door grab handle moulding (see Illustrations) 4 Prise the electric window/mirror adjustment switch from the armrest and unplug the wiring connector(s). Label them to aid correct refitting later (see illustrations).
14.4a Prise the electric window/mirror adjustment switch from the armrest... 14.4b ... and unplug the wiring connector

12*2 Body electrical systems
3 Electrical problems usually stem from simple causes, such as loose or corroded connections, a faulty earth connection, a blown fuse, a melted lusible link, or a fautty relay {refer to Section 3 for details of testing relays). Visually inspect the condition of all (uses, wires and connections in a problem circuit before testing the components. Use the wiring diagrams lo determine which terminal connections will need to be checked, in order to pinpoint the trouble-spot. 4 The basic tools required for electrical fault-finding include a circuit tester or voltmeter (a 12-volt bulb with a set of lest leads can also be used for certain tests}; a self-powered test light (sometimes known as a continuity tester); an ohmmeter (to measure resistance): a battery and set of tesi leads: and a lumper wire, preferably with u circuit breaker or fuse incorporated, which can be used to bypass susoect wires or electrical components. Before attempting to locate a problem with tost instruments, use the wiring diagram to determine where to make the connections. 5 To find the source of an intermittent wiring fault (usually due to a poor or dirty connection, or damaged wiring Insulation), a wiggle test can be performed on the wiring. This involves wiggling the wiring by hand, to see if tha fault occurs as the wiring Is moved. It should be possible to narrow down the source of the fault to a particular section of wiring. This method of testing can be used in conjunction with any of the tests descnbed in the following sub-Sections. 6 Apart from problems due to poor connections, two basic types of fault can occur in an electrical circuit - open-circuit, or short-circuit. 7 Open-circuit faults are caused by a break somewhere in the circuit, which prevents current from flowing. An open-circuit fault will prevent a component from working, but will not cause the relevant circuit fuse to blow 8 Short-circuit faults are caused by a shod somewhere in the circuit, which allows Die current flowing In the circuit to escape along an alternative route, usually to earth. Short-circuit faults are normally caused by a breakdown in wiring insulation, which allows a feed wire to touch either another wire, or an earthed component such as the bodysheli. A short-circuit fault will normally cause the relevant circuit fuse to blow.
Finding an open-circuit 9 To check for an opon-circuit, connect one lead of a circuit tester or voltmoter to either the negative battery terminal or a known good earth. 10 Connect the other lead to a connector in the circuit being tested, preferably nearest to the batter/ or luse. 11 Switch on the circuit, bearing In mind that some circuits are live only when tho ignition switch is moved to a particular position. 12 If voltage is present (Indicated either by
3.2 Main fuse box, located on the driver's side of the facie the toster bulb lighting or a voltmeter reading, as applicable), this means that tho section of Ihe circuit between the relevant connector and the battery is problem-free. 13 Continue to check the remainder ot the circuit in the same fashion. 14 When a point is reached at which no voltage Is present, the problem must lie between that point and the previous test point with voltage. Most problems can be traced to a broken, corroded or loose connection.
Finding a short-circuit 15 To check for a short-circuit, first disconnect the load(s) from the circuit (loads are the components which draw current from a circuit, such as bulbs, motors, heating elements, etc). 16 Remove the relevant luse Irom the circuit, and connect a circuit tester or voltmeter to the luse connections. 17 Switch on the circuit, beanng in mind that some circuits are live only when the ignition switch is moved to a particular position. 18 If voltage is present (indicated either by the tester bulb lighting or a voltmeter reading, as applicable), this means that there Is a short-circuit. 19 If no voltage is present, but the fuse still blows with the load(s) connected, this indicates an internal fault in the load(s).
Finding an earth fault 20 The battery negative terminal Is connected to 'earth' - the metal of the engine/transmission and the car body - and
I
IK
J 3.3 To gain access to the fuses, remove the screw and pull the stowage bin away from the facia
most systems are wired so that they only receive a positive feed, the current returning via the metal of Ihe car body. This means that the component mounting and the body form part of that circuit. Loose or corroded mountings can therefore cause a range of electrical faults, ranging from total failure ot a circuit, to a puzzling partial fault. In particular, lights may shine dimly (especially when another circuit sharing the same earth port In operation), motors (eg wiper motors v Ihe radiator cooling fan motor) may run slowly, and Ihe operation of one circuit may have an apparently-unrelated effect on another. Ncie that on many vehicles, earth straps axe uses between certain components, such as the engine/transmission and the body, usually whore there is no metal-to-metal contact between components, due to flexible rubber mountings, etc. 21 To check whether a component $ properly earthed, disconnect Ihe battery, and connect one lead of an ohmmeter to a kwwi good earth point. Connect the other lead to the wire or earth connection being tested. Tha resistance reading should be zero; if not. check the connection as follows. 22 If an earth connection Is thought to be faulty, dismantle the connection, and clean pack to bare metal both the bodysheli and ite wire terminal or the component earth connection mating surface. Be careful to remove all traces of dirt and corrosion, then use a knife to trim away any palm, so thai a clean metal-to-metal joint Is mads. On reassemoly, tighten the joint fasteners securely: if a wire terminal Is being refitted, use serrated washers between tho terminal and the bodysheli. to ensure a clean and secure connection. When the connection is remade, prevent the onset ot corrosion in the future by applying a coat of petroleum idly
or
stlicone-based grease, or by spraying on (a: regular intervals} a proprietary ignition eoater, or a water-aispersant lubneant.
3 Fuses and relays -general information
Fuses 1 Fuses are designod to break a circuit when a predetermined current is reached, in order to protect the components and wiring wttioh could be damaged by excessive current How. Any excessive current flow will be due to a fault in the circuit, usually a short-circuit (see Section 2). 2 The main fuses are located in the fusefcox on the driver's side of the facia (see illustration). 3 To gain access to the fuses, remove tne screw and pull the stowage bin moulding away from the facia (see illustration). 4 Additional fuses and circuit-breakers are located In the engine compartment, and in an