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

Step

Action

Value(s)

Yes

No

1

Was the Defogger System Check performed?

--

Go to Step 2

Go to Defogger System Check

2
  1. Remove the Rear Window Defogger Relay
  2. Connect a J 39200 between the Rear Window Defogger Relay cavity A2 for the PPL (293) wire and a known good ground.
  3. Measure voltage at this point.

Is voltage greater than the specified value?

1 V

Go to Step 3

Go to Step 4

3

Locate and repair the short to B+ in PPL (293) wire.

Is the repair complete?

--

Go to Defogger System Check

--

4
  1. Turn the ignition OFF.
  2. Connect a J 39200 between the Rear Window Defogger Relay cavity A1 for the ORN (267) wire and a known good ground.
  3. Measure the voltage at this point.

Is the voltage measured above the specified value?

1 V

Go to Step 5

Go to Step 7

5
  1. Disconnect connector C3 at the Heater and A/C Controller.
  2. Connect a J 39200 between the Rear Window Defogger Relay cavity A1 for the ORN (267) wire and a known good ground.
  3. Measure the voltage at this point.

Is the voltage measured above the specified value?

1 V

Go to Step 6

Go to Step 8

6

Locate and repair the short to B+ in the ORN 267 wire.

Is the repair complete?

--

Go to Defogger System Check

--

7

Replace the Rear Window Defogger Relay.

Is the repair complete?

--

Go to Defogger System Check

--

8

Replace the Heater and A/C Controller

Is the repair complete?

--

Go to Defogger System Check

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