GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1998 🢒 Sonoma Pickup - 4WD 🢒 HVAC 🢒 HVAC Systems - Automatic 🢒 Blower Has High Speed Only

Step

Action

Value(s)

Yes

No

1

Was the Diagnostic System Check performed?

--

Go to Step 2

Go to Diagnostic System Check

2
  1. Turn the ignition to the OFF position.
  2. Disconnect the heater and A/C control electrical connector.

Is the blower operating at maximum speed?

--

Go to Step 3

Go to Diagnostic System Check

3

Replace the PWM power module.

Is the repair complete?

--

Go to Diagnostic System Check

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