Braking system 9®7
5JJc ... and disconnect the handbrake cable from the brake shoe lever
5.14a Lower return spring fitted in place
12 Fit the self-adjuster mechanism Into the recess in the trailing brake shoe and anchor the retaining spring in the slot provided in the shoe (see Illustration). 13 Fit the leading shoe In position on the backpiste and secure it with the hold down pin. spring and cup as described for the trailing shoe. Engage the end of'the self-adjuster mechanism with the recess In the leading brake shoe. Hook the retaining spring into the slot provided. 14 Fit the upper and lower shoe return spnngs. engaging them with the slots In the shoes as shown (see illustrations). Remove
me
elastic band from the wheel cylinder. 15 Turn Ihe serrated wheel at the end of the self-adjuster mechanism, to retract the brake shoes - this will give additional clearance to ilow Ihe drum to pass over the shoes during refitting. 16 Repeat the procedure on the remaining tide of the vehicle. 17 Refit the brake drums as described in Section 6. Check and if necessary adjust the operation of the handbrake, as described in Section 9. IB Apply the brake pedal and handbrake 'ever several times to settle the self-adjusting mechanism. With both rear roadwheels rsfitted and Ihe rear of the vehicle still raised, turn Ihe wheels by hand to check that the take shoes are not binding. 19 Lower the vehicle to the ground and thoroughly check the operation of the braking system.
5.10 Apply brake grease sparingly to the shoe contact surfaces (arrowed) of the brake backplate
5.14b Correct location of upper return spring In leading shoe...
6 Rear brake drums -removal, inspection and refitting ^
A
Warning: Before starting work, refer to the warning at the beginning of Section 2 concerning the dangers of asbestos dust Removal 1 Chock the front wheels, then jack up the roar of the vehicle and support it on axle stands (see Jacking and vehicle support). Remove the appropriate rear roadwheel. Fully release the handbrake. 2 If the original drum is to be refitted, mark the relationship between the drum and the hub. Slacken and remove the two locating studs and pull the drum from the hub (see illustration).
6.2 Slacken and remove the two drum locating studs
5.12 Fit the self-adjuster mechanism into the recess (arrowed) in the trailing brake shoe
5.14c ... and trailing shoe
3 If the drum is binding on Ihe brake shoes, it can be drawn off as follows. Hold the drum still and turn the hub so that the drum and hub flange bolt holes no longer line up. Screw two bofts into the locating stud threaded holes In tho drum, and progressively lighten them against the hub llange to push the drum from the hub (see illustration).
Inspection Note: If either drum requires renewal, BOTH should be renewed at the same time, to ensure even and consistent braking. New brake shoes should also be fitted. 4 Working carefully, remove all traces of brake dust from the drum, but avoid Inhaling the dust, as it is a health hazard. 5 Clean the outside of the drum, and check it for obvious signs of wear or damage, such as cracks around the roadwheel stud holes; renew the drum if necessary.
6.3 Using two bolts to draw the drum off the brake shoes
9*8 Braking system
6 Carefully examine the Inside of tho drum. Light scoring of the friction surface is normal, but if heavy scoring Is found, the drum must be renewed. 7 It is usual to find a lip on the dmm's inboard edge which consists of a mixture of rust and brake dust: this should be carefully scraped away, to leave a smooth surface which can be polished with fine (120 to 150-grade) emery paper. If, however, the tip is due to the friction surface being recessed by excessive wear, then the drum must be renewed. 6 If the drum Is thought to be excessively worn, or oval, its internal diameter must be measured at several points using an internal micrometer. Take measurements In pairs, the second at right-angles to the first, and compare the two, to check for signs of ovality. Provided that it does not enlarge the dium to beyond the specified maximum diameter, it may be possible to have the drum refinished by skimming or grinding; if this is not possible, Ihe drums on both sides must be renewed. Note that if the drum is to be skimmed, BOTH drums must be refinished. to maintain a consistent Internal diameter on both sides.
Refitting 9 II a new brake drum is to be Installed, use a suitable solvent to remove any preservative coating thai may have been applied to its internal fnction surfaces. Note that it may also be necessary to shorten the adjuster strut length, by rotating the sedated strut wheel, lo allow Ihe drum lo poss over the brake shoes • see Section S for details. 10 II tho original dfum is being refitted, align the marks made on the drum and hub before removal, then lit the drum over the hub. Refit the locating studs and tighten them to the specified torque. 11 Depress the footbrake repeatedly to expand the brake shoes against the drum, and ensure that normal pedal pressure Is restored. 12 Check and if necessary adjust the handbrake cable as described In Section 9. 13 Refit tho roadwheels, and lower the vehicle to the ground.
7 Rear wheel cylinder -removal, overhaul and refitting jS
A
Warning: Before starting work, refer to the warnings at tho beginning of Sections 2 and 11 concerning the dangers ot handling asbestos dust and hydraulic fluid.
Removal 1 Remove the brake drum fsee Section 6). 2 Remove the brake shoes (see Section 5). 3 To minimise fluid loss during the following operations, remove the master cylinder reservoir cap. then tighten it down onto a piece of polythene, lo obtain an airtight seal.
the hydraulic pipe from the rear of the wheel cylinder 4 Clean the brake backplate around Ihe wheel cylinder mounting boits and the hydraulic pipe union, then unscrew the union nut and disconnect Ihe hydraulic pipe (see illustration). Cover the open ends of the pipe and the master cylinder to prevent dirt ingress, 5 Remove the securing bolts, then withdraw the wheel cylinder from the backplate (soe Illustration).
Overhaul Note: Before commencing woric, ensure that the appropriate wheel cylinder overhaul kit is obtained. 6 Clean tho assembly thoroughly, using only methylated spirit or clean brake fluid, 7 Peel off both rubber dust covers, then use paint or similar to mark one ot the pistons so that the pistons are not interchanged on reassembly. 8 Withdraw both pistons and tho spring. 9 Discard the rubber piston cups and the dust covers. These components should be renewed as a matter of course, and are available 3s part of an overhaul kit, which also Includes the bleed nipple dust cap. 10 Check the condition of the cylinder bore and the pistons - the surfaces must be perfect and free from scratches, scoring and corrosion, It is advisable to renew the complete wheel cylinder if there is any doubt as to the condition ot the cylinder bore or pistons. 11 Ensure thai all components are clean and dry. The pistons, spring and cups should be
8.4 Location of brake tight switch-LHD model shown
withdraw the wheel cylinder from the backplate fitted wet, using hydraulic fluid as a lubricant • soak them in clean fluid before installation. 12 Fit the cups to the pistons, ensuring that they are the correct way round. Use only your fingers (no tools) to manipulate the cups into position. 13 Fit the first piston to the cylinder, taking care not to distort the cup. If the original pistons are being re-used, ihe marks
made on
dismantling should be used to ensure that the pistons are refitted to their original bores, 14 Refit the spring and the second pfston. 15 Apply a smear of rubber grease to Ihe exposed end of each piston and to the dust cover sealing lips, then fit Ihe dust covers to each end of the wheel cylinder.
Refitting 16 Refitting is a reversal of removal, bearirg in mind the following points: a) Tighten the mounting bolts to the specified torque. b) Refit the brake shoes as desenbod
In
Section 5. and refit the brake drum
as
described in Section 6. c) Before refitting the roadwheel
and
lowering the vehicle to the ground, remove the polythene from the fluid reservoir, and bleed the hydraulic
system
as described in Section f
1.
Note that if
nc
other part of the system has been disturbed, it should only bo necessary
to
bleed the relevant rear circuit.
8 Stop-light switch • & adjustment, removal J? and refitting
Adjustment 1 The switch plunger operates on a ratchet 2 If adjustment Is required, pull the plunge fully out - (he 9witch then sell-adjusts as the brake pedal Is applied and released.
Removal 3 Ensure that the ignition Is switched to OfF. 4 For Improved access, remove the driver's side lower facia panel, as described in Chapter 11 (see Illustration). 5 Disconnect the wiring plug from the switch.
Braking system 9®9
6.8 Brake light switch assembly f Hexagonal' 3 Spacer section 4 Mounting bracket 2 Bush S Locating lug 6 Twist the switch anti-clockwise through about half a turn, and withdraw the switch from the pedal bracket. Note the position of the spacer and fitting bush.
10.3a Prise the bung (arrowed) from the access hatch in the rear of the relevant brake backplate
10.3b Unhook the cable end from the brake shoe lever (arrowed)
Refitting 7 Depress the brake pedal and hold it in this position. 8 Fit the bush and spacer over the end of the switch, then Insert the switch Into its mounting bracket. Rotate the switch body clockwise through 60° until the locating lug is felt to engage in its recess (seo illustration). 9 Release the brake pedal and allow It to rest against the switch spacer tab - this adjusts the position of the switch body Inside Ihe bush. 10 Now depress the brake pedal again - this has the effect of breaking off the spacer tab and fixes the position of the switch Inside the bush. 11 Restore Ihe wiring at the connector, then refit the facia lower trim panel. 12 Switch on the ignition and test the operation of the brake lights.
9 Handbrake - ^ checking and adjustment
Checking 1 Apply the handbrake by pulling it through three to four clicks of the ratchet mechanism and check that this locks the rear wheels, holding the vehicle stationary on an incline. In this position, there should be sufficient reserve travel in the handbrake lever to allow for brako shoe wear and cable stretching. If not. Ihe handbrake mechanism Is need of adjustment.
Adjustment 2 Remove the securing screws and lift off the handbrake lever trim cover - refer to Chapter 11. Section 19. for details. 3 Pull the handbrake lever through three clicks of the ratchet mechanism and leave it in this position. 4 The adjustment mechanism is underneath the handbrake lever. Hold the locknut with a ring spanner, then rotate the adjustment screw through one turn anticlockwise, so that the adjustment mechanism tensions the handbrake cable draw bar (see illustration). 5 Release the handbrake lever, then re-apply
10.5a Unscrew the bolts (arrowed) securing the handbrake cable bracket to the suspension lower arm
the handbrake it and check the operation of the handbrake as described in paragraph 1. Repeat the adjustment procedure as necessary. 6 Chock the front wheels then |ack up the rear of the car and support it on axle stands (see Jacking and Vehicle Support). Release the handbrake lever and check that the rear wheels are free to rotate v/ithout binding. Re-adjust the cable if the brakes appear to be binding. 7 On completion, tighten the cable locknut and refit the handbrake lever trim cover. Lower the car to the ground.
10 Handbrake cables -removal and refitting
Removal 1 There are two rear handbrake cables, one on each side of the vehicle. To renew either rear cable, proceed as follows. 2 Chock the front wheels, then jack up the rear of tho vehicle and support securely on axle stands (see Jacking and vehicle support). Release the handbrake fully, 3 Working under the rear of the car, prise the bung from the access hatch in the rear of the relevant brake backplato, Using pointed-nose pliers, compress the cable spring and release the cable end from the brake shoe lever (see Illustrations). 4 Extract the handbrake outer cable from the brake backplate. then withdraw the end of the cable from the brake assembly. 5 Unscrew the nuts and bolts securing the handbrake cable bracket to the suspension lower arm. Release the cable from the clips on the floorpan heatshield (see Illustrations).
10.5b Release the cable from the clips (arrowed) on the floorpsn heatshield
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
9*12 Braking system
master cylinder mounting nuts, and tighten them securely. 10 Wipe clean the brake pipe unions, then refit them to the correct master cylinder ports, as noted before removal, and lighten the union nuts securely. 11 Refill tha master cylinder reservoir with new fluid, and bleed the complete hydraulic system as described In Section 11. 12 Check the operation of the braking system thoroughly.
13 Hydraulic pipes and hoses - % renewal S§
A
Warning: Before starting work, refer to the warning at the beginning of Section 11 concerning the dangers of hydraulic fluid, 1 If any pipe or hose is to be renewed, minimise fluid loss by first removing the master cylinder reservoir cap. then tighten the cap down onto a piece of polythene to obtain
an airtight seal. Alternatively, flexible hoses can be sealed, If required, using a proprietary brake hose clamp; metal brake pipe unions can be plugged (if care Is taken not to allow dirt into the system) or capped immediately they are disconnected. Place a wad of rag under any union that is to be disconnected, to catch any spilt fluid-2 If a flexible hose Is to be disconnected, unscrew the brake pipe union nut before removing the spring clip which seeurea the hose to its mounting bracket. 3 To unscrew the union nuts, ll is preferable lo obtain a brake pipe spanner of the correct size; these are available from most large molor accessory shops. Failing this, a close-fitting open-ended spanner will be required, though if the nuts are tight or corroded, their flats may be rounded-off if the spanner slips. In such a case, a self-locking wrench is often the only way to unscrew a stubborn union, but It follows that Ihe pipe and the damaged nuts must be renewed on reassembly. Always clean a union and surrounding area before disconnecting it If disconnecting a compo-
nent with more than one union, make a carefJ note of the connections before disturbing
any
of them. 4 If a brake pipe Is to be renewed, it can b« obtained, cut to length and with the union nuts and end flares in place, from Fiat dealers. All that is then necessary is to bend It to shape, following the line of the original, baton fitting It to the vehicle. Alternatively, most motor accessory shops can make up bra Ha pipes from kits, bul this requires very carefii measurement of the original, to ensure (hat the replacement is of the correct length. Tha safest answer is usually to take the original lo the shop as a pattern. 5 On refitting, do not overtighten the union nuts. It is not necessary to exercise brute force to obtain a sound joint. 6 Ensure that the pipes and hoses an correctly routed, with no kinks, and that they are secured in the clips or brackets provided. After fitting, remove the polythene from lbs reservoir, and bleed the hydraulic system
88
described In Section 11. Wash off any split fluid, and check carefully for fluid leaks.
10*1
Chapter 12
Body electrical systems
Contents
Bulbs (exterior lights) - renewal 4 Bulbs (interior lights) - renewal 5 Electrical fault finding - general information 2 Exterior light units - removal and refitting 6 Fuses and relays - general Information 3 General information and precautions 1 Headlight beam alignment • general Information 6 Horn • removal and refitting 9 Instrument panel - removal and refitting 7 Loudspeakers - removal and refitting 10
Degrees of difficulty
Radio aerial - removal and refitting 11 Radio/cassette player • removal and refitting 12 Speedometer drive cable - removal and refitting 13 Switches - removal end refitting 14 Tailgate wiper motor - removal and refitting 15 Windscreen wiper motor - removal and refitting 17 Windscreen/tailgate washer system components • removal and refitting 16 Wiper arm • removal and refitting 18
Easy,
statable for ^
novice with liffle
|| experience ^
Fairly
easy,
suitable for beginner with ^ some experience ^
Fabtycffficiit,
suitable
for competent ^
DIY
mechanic ^
Difficult, suitable for
^ experienced DIY JR mechanic
Very difficult,
A,
suitable
for
expert DIY
Sj or professional ^
Specifications
Bulb ratings Watts Headlights 60/55 Front long range driving light 55 Front fogllght 55 Front direction Indicator light 21 Front sidelight 5 Front direction indicator repeater light 5 Stop light 21 Tall light 5 Rear direction indicator light 21 Reversing light 21 near fogllght 21 Hear number plate light 5 Courtesy light 10 Map reading light 5
1 Genera! information and precautions
A
Warning: fie/Ore carrying out any work on the electrical system, read through the precautions given in Safety first! at the beginning of this manual, and in Chapter 8. The electrical system is of 12-volt negative earth type. Power for the lights and all electrical accessories is supplied by a lead/acid type battery, which is charged by the alternator. This Chapter covers repair and service procedures for the various electrical components not associated with the engine. Information on the battery, alternator and starter motor can be found in Chapter 5. It should be noted that, prior to working on any component In the electrical system, the
battery negative terminal should first be disconnected, to prevent the possibility of electrical short-circuits and/or fires. Caution: Before proceeding, refer to Disconnecting the battery In the Reference Section of this manual for further information.
2 Electrical fault finding-general information
Note: Refer to the precautions given In Safety first! and in Section 1 of this Chapter before starting work. The following tests relate to testing ot the main electrical circuits, and should not be used to test delicate electronic circuits (such as antHock braking systems), particularly where an electronic con fro/ module is used.
General 1 A typical electrical circuit consists of an electrical component, any switches, relays, motors, fuses, fusible links or circuit breakers related to that component, and the wiring and connectors which link the component to both the battery and the chassis. To help to pinpoint a problem in an electrical circuit, wiring diagrams are Included at the end of this manual. 2 Before attempting to diagnose an electrical fault, first study the appropriate wiring diagram, to obtain a more complete understanding of the components included In the particular circuit concerned. The possible sources of a fault can be narrowed down by noting whether other components related to the circuit are operating properly. If several components or circuits fait at one time, the problem Is likely to be related to a shared fuse or earth connection.