GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 1999 🢒 Grand Prix 🢒 Body and Accessories 🢒 Stationary Windows 🢒 Rear Window Defogger Always On

Step

Action

Value(s)

Yes

No

1

Did you perform the Defogger System Check?

--

Go to Step 2

Go to Defogger System Check

2
  1. Disconnect the rear window defogger relay.
  2. Turn the ignition switch to the RUN position.
  3. Use a test lamp to probe between B+ and the rear window defogger relay connector terminal A1 (circuit 193).

Does the test lamp light?

--

Go to Step 5

Go to Step 3

3

Use a test lamp to probe between the rear window defogger relay connector terminal A2 (circuit 293) and ground.

Does the test lamp light?

--

Go to Step 8

Go to Step 4

4
  1. Replace the rear window defogger relay.
  2. Inspect the system again.

Is the repair complete?

--

Go to Defogger System Check

Go to Step 3

5

Inspect for a short to ground in circuit 193 (WHT).

Did you find a short to ground on the circuit?

--

Go to Step 6

Go to Step 7

6
  1. Repair the short to ground in circuit 193 (WHT).
  2. Inspect the system again.

Is the repair complete?

--

Go to Defogger System Check

Go to Step 5

7

Replace the Heater A/C Control. Refer to the following procedures:

    •  Control Assembly Replacement for Manual HVAC Systems
    •  Control Assembly Replacement for Automatic HVAC Systems

Is the repair complete?

-

Go to Defogger System Check

Go to Step 5

8
  1. Repair a short to B+ in circuit 293 (PPL).
  2. Inspect the system again.

Is the repair complete?

--

Go to Defogger System Check

Go to Step 3