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Troubleshooting by Symptom
Poor Heater System Performance
CAUTION
Check all fluid levels and adjust as needed, before operating vehicle for extended periods
at idle.
1. Start the engine.
2. Idle the engine until the thermostat opens (upper radiator hose will be hot) Is the
engine at normal operating temperature (approx. 200° F)? If yes, go to the next
step. If no, go to step 16.
3. Set the mode selector to FLOOR mode.
4. Set the heater control selector to the warmest temperature setting.
5. Set the blower speed the lowest setting.
6. Carefully feel the inlet and outlet heater hoses at the heater core. Is the inlet heater
hose significantly hotter than the outlet heater hose? If yes, go to step 14. If no, go
to the next step.
7. Set the mode selector to PANEL mode.
8. Select the maximum blower speed.
9. Select the warmest temperature setting.
10. Place a thermometer into the center I/P PANEL air outlet and affix a second
thermometer to the heater core outlet heater hose.
11. Record the temperature at the center I/P PANEL air outlet and at the heater core
outlet heater hose. Are the two temperature readings about equal? If yes, go to the
next step. If no, go to step 13.
12. Inspect and repair the cowl, cowl area, recirculation door, and the HVAC
evaporator/heater core case for cold air leaks. Repair any problems found, go to
step 17.
13. Inspect the temperature door operation. Repair any problems found, go to step 17.
14. Turn OFF the engine. Back-flush the heater core. Start the engine. Select the
FLOOR mode and the lowest blower speed. Select the warmest temperature
setting. Feel the temperature of the inlet and outlet heater hoses at the heater core.
Is the inlet heater hose feel significantly hotter than the outlet heater hose? If yes,
go to the next step. If no, go to step 17.
15. Replace the heater core. When the repair is completed, go to step 17.
16. Check for low engine temperature problems, Repair or replace as needed, go to
step 17.
17. Operate the system in order to verify the repair. If the system operates properly,
the repair is complete. If the heater still does not work properly, repeat the entire
procedure.
Содержание TrailBlazer
Страница 1: ......
Страница 26: ...Fig 3 Typical body and undervehicle maintenance locations Refer to chart for descriptions ...
Страница 29: ......
Страница 30: ......
Страница 31: ......
Страница 59: ...Cylinder head bolt removal and installation 32 Remove and discard the bolts from the cylinder head ...
Страница 175: ...Spring free length check Valve spring squareness check ...
Страница 192: ...Front of piston mark ...
Страница 361: ...5 3L Engine Except Saab Underhood Fuse Block 2003 2005 Early Production ...
Страница 469: ...Removing the outer band from the CV boot Removing the inner band from the CV boot ...
Страница 470: ...Removing the CV boot from the joint housing Clean the CV joint housing prior to removing boot ...
Страница 471: ...Removing the CV joint housing assembly Removing the CV joint ...
Страница 472: ...Inspecting the CV joint housing Removing the CV joint outer snap ring ...
Страница 473: ...Checking the CV joint snap ring for wear CV joint snap ring typical ...
Страница 474: ...Removing the CV joint assembly Removing the CV joint inner snap ring ...
Страница 475: ...Installing the CV joint assembly typical ...
Страница 506: ...Tie Rod End Removal Installation Inner Tie Rod End To Remove Inner tie rod assembly Magnasteer ...
Страница 553: ...9 Torque the lug nuts to specification 10 Lower the vehicle ...
Страница 556: ...Toe in Frame Misalignment Frame misalignment ...
Страница 588: ...Bleeding caliper ...
Страница 596: ...Inboard brake pad removal and installation 10 Remove the inboard brake pad from the brake caliper ...
Страница 624: ...Manifold gauge set components Refrigerant recovery recycling station ...
Страница 662: ...Lower instrument panel retaining volts 25 Remove the lower retaining bolts from the instrument panel I P ...
Страница 676: ...A C Specifications ...
Страница 677: ......