GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 1998 🢒 Grand Prix 🢒 Body and Accessories 🢒 Stationary Windows 🢒 Rear Window Defogger Always On

Step

Action

Value(s)

Yes

No

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

Does the test lamp light?

--

Go to Step 4

Go to Step 2

2

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

Does the test lamp light?

--

Go to Step 7

Go to Step 3

3
  1. Replace the rear window defogger relay.
  2. Inspect the system again.

Is the repair complete?

--

System OK

--

4

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

Is there a short to ground on the circuit?

--

Go to Step 5

Go to Step 6

5
  1. Repair the short to ground in CKT 193 (WHT).
  2. Inspect the system again.

Is the repair complete?

--

System OK

--

6

Replace the heater - A/C control:

  1. Refer to Control Assembly Replacement for Manual HVAC Systems
  2. Refer to Control Assembly Replacement for Automatic HVAC Systems.

Is the repair complete?

-

System OK

--

7
  1. Repair a short to B+ in CKT 293 (PPL).
  2. Inspect the system again.

Is the repair complete?

--

System OK

--