GMC 1986 P-Truck Service Manual page 55

1A-16 HEATING
11 /4-inch (32 mm) minimum clearance between the
auxiliary heater core lines and the exhaust pipe. Refer
to figure 15.
HEATER DISTRIBUTOR AND
CORE ASSEMBLY
0
Remove or Disconnect (Figures 15, 16 and 17)
1. Battery ground cable.
2. Coolant recovery tank.
3. Heater core hoses (figure 15).
— Place a clean pan under the vehicle to catch
any coolant spillage.
— Plug the hoses.
— Allow coolant in the core to drain into the
pan.
4. Heater distributor duct (figure 16).
— Remove the screws that hold the distributor
duct to the d is trib u to r case and the
distributor duct to the engine cover.
5. Engine housing cover.
— Remove the screws at the windshield, all
lower screws and the right instrument panel
support bracket at the door pillar and the
engine housing.
6. Instrument panel.
7. Lower the steering column.
* Raise and support the right side of the in­
strument panel.
8. Defroster duct to distributor case attaching
screws.
9. Distributor to heater case (2!) screws.
10. Temperature door cable (figure 17).
— Fold the cable back for access.
11. Heater case and core.
— Three nuts at the engine compartment side
of the distributor case and one screw on the
passenger side.
— Tilt the case assembly rearward at the top
while lifting up until the core tubes clear the
dash openings.
12. Core retaining strap screws (figure 15).
13. Core.
+ 4-
Install or Connect (Figures 15, 16 and 17)
1. Core to the heater case.
2. Sealer between the core and case.
3. Core retaining strap screws.
4. Apply new sealer between the heater case and
the opening in the vehicle.
5. Heater core and case to the vehicle.
• Tilt the case until the core tubes clear the
cowl opening.
6. Temperature door cable.
7. Distributor duct to the heater case.
8. Defroster duct to the distributor case.
9. Instrument panel.
10. Steering column.
11. Engine housing cover.
12. Heater distributor duct.
13. Heater core hoses.
14. Coolant recovery tank.
15. Battery ground cable.
DISTRIBUTOR AND
DEFROSTER DUCTS
Remove or Disconnect (Figure 16)
1. Battery ground cable.
2. Raise the instrument panel at the right side.
Refer to " Heater Distributor and Core Assembly."
3. Engine cover.
— Unsnap the engine cover front latches and
remove the two cover-to-floor pan screws.
4. Screws that hold the heater distributor duct to the
heater case.
5. Screw at the left center of the distributor duct.
6. Distributor duct.
• Pull the center distributor duct to the right.
7. Defroster duct.
• Screws that hold the defroster duct to the
instrument panel.
+ 4 j Install or Connect (Figure 16)
1. Defroster duct.
2. Distributor duct.
3. Engine cover.
4. Instrument panel.
5. Battery ground cable.
CONTROL ASSEMBLY
REPLACEMENT
Remove or Disconnect (Figure 17)
1. Battery ground cable.
2. Instrument panel bezel.
3. Control out of the instrument panel (figure 17).
• Pull the control out to reach the bowden
cable.
4. Bowden cables.
5. Control illumination bulb.
6. Blower switch connector.
7. Control from the vehicle.
8. Blower switch.