Removal (Montero)
1) Move temperature control lever to WARM position. Drain
coolant from vehicle. Disconnect heater hoses from heater unit. See
Fig. 1.
2) Remove lap heater ducts. Remove hood release bracket.
Using screwdriver, release tabs and remove left and right demister
grilles. Remove glove box frame attaching screws, and remove glove
box. Remove passenger lap heater duct.
3) Using screwdriver and shop towel, carefully pry at top
center of instrument cluster cover, and remove cover. Remove 2 screws
at bottom of instrument panel and one bolt at top of instrument panel.
Gently pull instrument cluster out, and disconnect speedometer cable
and electrical connections. Remove instrument cluster.
4) Remove 4 screws, and disconnect electrical connections on
back of instrument cluster. Remove instrument cluster. Handle
instrument cluster carefully. Instrument cluster can be damaged if
dropped.
5) Remove center console knobs and side screw plugs. Remove
screws, disconnect electrical connections and remove console. Remove 6
bolts and console bracket (center dash reinforcement). Disconnect
radio connections while removing console bracket.
6) Remove horn pad and steering wheel retaining nut. Mark
steering wheel and steering shaft for reassembly reference. Using
steering wheel puller, remove steering wheel.
7) Using screwdriver, carefully pry out dash plug at upper
center of dash panel. Remove 3 upper dash mounting nuts, one upper
screw above steering column, and 2 lower mounting screws. Remove dash
panel.
8) Remove control cables at heater unit. Remove heater unit
attaching screws. Remove heater ducts. Remove heater unit. Remove
heater control lever arm.
9) Remove heater control valve cover. Remove heater pipe and
heater control valve. Disconnect control arm linkage. Remove control
arm. Remove heater core by moving it sideways.
Installation
1) To install, reverse removal procedure. Insert heater hoses
fully into pipes, and clamp securely to prevent leaks. Connect heater
hoses with 1-1.2" (25-30 mm) overlap on outlet.
2) When filling radiator with coolant, first open heater
control valve fully and run engine to circulate coolant and discharge
air from inside heater and engine cooling system. Stop engine, and add
coolant.
3) Adjust all control cables. When installing heater hose
grommets, apply sealer. After installing heater control assembly,
ensure each lever operates smoothly.
Removal (Pickup & Ram-50)
1) Disconnect battery ground cable. Place heater control
lever to far right. Drain coolant. Using trim stick, pry out hazard
switch and remove electrical connection. Remove 4 instrument cluster
cover screws, and remove cover. Remove 4 instrument cluster screws.
Tilt instrument cluster out, and disconnect speedometer cable and
electrical connections. Remove cluster.
2) Remove fuse box cover and fuse box assembly. Remove glove
box. Remove defroster air ducts. Disconnect heater control cables.
Using trim stick, pry under and remove speaker grilles. Remove clock
or coin box in center of dash. Remove center dash hole cover (located
above clock).
3) Remove 2 center support cover screws, and remove cover.
Remove shift knob and 6 console attaching screws. Remove console.
Ensure all electrical connections are free of dash panel. Remove 3 top
nuts, one bolt above steering column, and side and lower attaching
EXAMPLE #2 - VOLTAGE CONTROLLED DRIVER
This time we will look at a GM 3.1L V6 VIN [T]. Fig. 8 shows
the 1, 3, 5 (odd) injector bank with the current waveform indicating
about a 2.6 amp draw at idle. This pattern, taken from a known good
vehicle, correctly stays at or below the maximum 2.6 amps current
range. Ideally, the current for each bank should be very close in
comparison.
Notice the small dimple on the current flow's rising edge.
This is the actual injector opening or what engineers refer to as the
"set point." For good idle quality, the set point should be uniform
between the banks.
When discussing Ohm's Law as it pertains to this parallel
circuit, consider that each injector has specified resistance of 12.2
ohms. Since all three injectors are in parallel the total resistance
of this parallel circuit drops to 4.1 ohms. Fourteen volts divided by
four ohms would pull a maximum of 3.4 amps on this bank of injectors.
However, as we discussed in EXAMPLE #1 above, other factors knock this
value down to roughly the 2.6 amp neighborhood.
Now we are going to take a look at the even bank of
injectors; injectors 2, 4, and 6. See Fig. 9. Notice this bank peaked
at 1.7 amps at idle as compared to the 2.6 amps peak of the odd bank (
Fig. 8 ). Current flow between even and odd injectors banks is not
uniform, yet it is not causing a driveability problem. That is because
it is still under the maximum amperage we figured out earlier. But be
aware this vehicle could develop a problem if the amperage flow
increases any more.
Checking the resistance of this even injector group with a
DVOM yielded 6.2 ohms, while the odd injector group in the previous
example read 4.1 ohms.
Fig. 8: Injector Odd Bank w/Normal Current Flow - Current Pattern