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Test N: Defrosting Insufficient

WARNING: This page is about a different car, the 2002 GMC Savana Special, 2002 GMC Savana Camper Special, 2002 GMC Savana, and 2002 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: For circuit reference, see CONNECTOR IDENTIFICATION  and/or WIRING DIAGRAMS  .
NOTE: Definition: Time required to defrost the windshield is longer than normal.
  1. Start engine. Select defrost mode. Select maximum blower speed. If sufficient air flows from defroster outlets, go to next step. If sufficient air does not flow from defroster outlets, go to step  9.
  2. Measure engine operating temperature. If engine reaches a normal operating temperature, go to next step. If engine does not reach a normal operating temperature, go to step  4.
  3. Select minimum blower speed. Select maximum temperature setting. Feel temperature of inlet and outlet hoses at heater core. If inlet hose feels warmer than outlet hose, go to step  5. If inlet hose does not feel warmer than outlet hose, go to step  11.
  4. Repair the low engine temperature concern. If repair is complete, go to step  13.
  5. Check compressor clutch operation. If clutch engages, go to step  7. If clutch does not engage, go to next step.
  6. Repair compressor clutch. See TEST L: COMPRESSOR CLUTCH DOES NOT ENGAGE - 6.5L DIESEL  or TEST M: COMPRESSOR CLUTCH DOES NOT ENGAGE - EXCEPT 6.5L DIESEL  . If repair is complete, go to step  13.
  7. Perform A/C system performance test. See A/C PERFORMANCE TEST  under PERFORMANCE TESTS. If A/C system is operating within specifications, go to next step. If A/C system is not operating within specifications, go to step  10.
  8. Check for correct operation of recirculation door. If recirculation door is operating correctly, go to step  13. If recirculation door is not operating correctly, go to step  12.
  9. Repair the improper air delivery concern. See TEST A: AIR DELIVERY IMPROPER . If repair is complete, go to step  13.
  10. Repair A/C system performance concern. See SYMPTOM TESTS . If repair is complete, go to step  13.
  11. Repair the heating concern. See HEATING PERFORMANCE DIAGNOSTICS WITH FRONT SYSTEM SHUT-OFF VALVE  or HEATING PERFORMANCE DIAGNOSTICS WITH AUXILIARY SHUT-OFF VALVE  under SYSTEM TESTS. If repair is complete, go to step  13.
  12. Repair the recirculation door operation concern. See MODE DOORS  under REMOVAL & INSTALLATION. If repair is complete, go to next step.
  13. Operate system to verify repair. If the condition was corrected, system is okay. If the condition was not corrected, return to step  1.
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