GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1998 🢒 Jimmy - 2WD 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 HVAC Blower Controls System Check

Step

Action

Normal Result(s)

Abnormal Result(s)*

1
  1. Turn the mode selector to the DEF position.
  2. Cycle the blower switch from the LOW position to the HIGH position.
  3. Repeat this action for the following positions:
    4. • BLEND
    • HEAT
    • VENT
    • BI-LEVEL
    • NORM
    • MAX A/C

The blower motor runs in all positions.
    •  Blower Motor Always On

2
  1. Turn the blower motor switch to HIGH.
  2. Turn the mode selector to the following positions:
    3. • DEF
    • BLEND
    • HEAT
    • VENT
    • BI-LEVEL
    • NORM
    • MAX A/C

The blower motor runs in all positions.
    •  Blower Motor Always On

* Refer to the appropriate symptom diagnostic table for the applicable abnormal result.