GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1999 🢒 Savana 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Rear Fog Lamps Inoperative

Step

Action

Value(s)

Yes

No

1

Was the Fog Lights System Check performed?

--

Go to Step 2

Go to Fog Lights System Check

2
  1. Remove the rear fog lamp relay.
  2. Connect a J 39200 DMM between rear fog lamp relay cavity A1 and a known good ground.

Is continuity present?

--

Go to Step 3

Go to Step 4

3
  1. Turn the headlamp switch to the HEAD position.
  2. Disconnect the rear fog lamp switch.
  3. Connect an unpowered test lamp to rear fog lamp switch cavity D to ground.

Did the test lamp light?

--

Go to Step 5

Go to Step 6

4
  1. Reinstall the rear fog lamp relay.
  2. Disconnect the rear fog lamp.
  3. Connect a J 39200 DMM between rear fog lamp connector cavity A and a known good ground.

Is continuity present?

--

Go to Step 7

Go to Step 8

5

Connect an unpowered test lamp from rear fog lamp relay cavity B1 to ground.

Did the test lamp light?

--

Go to Step 9

Go to Step 10

6

Repair the open in CKT 10 (YEL) between the headlamp switch and the rear fog lamp switch. Refer to Headlights/Daytime Running Lights (DRL) Schematics or Headlights Schematics .

Is the repair complete?

--

Go to Fog Lights System Check

--

7
  1. Connect an unpowered test light between rear fog lamp cavity B and a known good ground.
  2. Place the headlamp switch in the head position.
  3. Actuate the rear fog lamp switch.

Did the test lamp light?

--

Go to Step 3

Go to Step 11

8

Repair the open in CKT 250 (BLK) between rear fog lamp cavity A and ground G401.

Is the repair complete?

--

Go to Fog Lights System Check

--

9
  1. Disconnect the rear fog lamp relay.
  2. Connect a J 39200 DMM from rear fog lamp relay cavity A3 to rear fog lamp switch cavity E.

Is continuity present?

--

Go to Step 12

Go to Step 13

10

Repair the open in CKT 10 (YEL) between the rear fog lamp relay and splice 250.

Is the repair complete?

--

Go to Fog Lights System Check

--

11

Repair the open in CKT 122 (RED) wire between the rear fog lamp relay and the rear fog lamp.

Is the repair complete?

--

Go to Fog Lights System Check

--

12
  1. Disconnect the rear fog lamp switch.
  2. Connect an unpowered test lamp from rear fog lamp switch cavity B to cavity D.

Did the test lamp light?

--

Go to Step 14

Go to Step 15

13

Repair the open in CKT 1977 (YEL) between the rear fog lamp relay and the rear fog lamp switch.

Is the repair complete?

--

Go to Fog Lights System Check

--

14
  1. Reconnect the rear fog lamp switch.
  2. Connect an unpowered test lamp from rear fog lamp relay cavity B3 to ground.

Did the test lamp light?

--

Go to Step 16

Go to Step 17

15

Repair the open in CKT 150 (BLK) between the rear fog lamp switch and ground G201.

Is the repair complete?

--

Go to Fog Lights System Check

--

16
  1. Connect an unpowered test lamp from rear fog lamp cavity B to ground.
  2. Connect a fused jumper from rear fog lamp relay cavity A3 to a known good ground.

Did the test lamp light?

--

Go to Step 18

Go to Step 19

17

Repair the open in CKT 340 (ORN) between the rear fog lamp relay and the IP fuse block DRL fuse.

Is the repair complete?

--

Go to Fog Lights System Check

--

18

Replace the rear fog lamp switch.

Is the repair complete?

--

Go to Fog Lights System Check

--

19

Replace the rear fog lamp relay.

Is the repair complete?

--

Go to Fog Lights System Check

--