GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1998 🢒 GMC C-Series Medium Duty Truck B7 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Turn Signal Lamps Inoperative

Step

Action

Value(s)

Yes

No

1

Check for a blown fuse, burned-out bulbs, and corrosion in the bulb sockets.

Is the repair complete?

--

System OK

Go to Step 2

2
  1. Set the turn signal switch to the left hand turn position and then to the right hand turn position.
  2. Observe the operation of the turn signal indicators on the instrument cluster.

Do the turn signal indicators flash?

--

Go to Step 3

Go to Step 9

3
  1. Set the hazard warning switch to the ON position.
  2. Observe the operation of the turn signal lamps.

Do the turn signal lamps work?

--

Go to Step 4

Go to Step 5

4

Repair the open connections in splices S223 and S224.

Is the repair complete?

--

System OK

--

5
  1. Disconnect the C200 connector.
  2. Examine the terminals and the terminal sockets to make sure that they are clean and free of corrosion, and that no terminals are bent or broken.
  3. Re-connect the C200 connector.

Is the repair complete?

--

System OK

Go to Step 6

6
  1. Disconnect the C102 connector.
  2. Connect a test lamp from C102 terminal C or from C102 terminal D to terminal G.
  3. Set the turn signal switch to the left or right position, whichever is appropriate.

Does the test lamp light?

--

Go to Step 7

Go to Step 8

7

Repair the open in CKT 150 (BLK) between C102 terminal G and S105.

Is the repair complete?

--

System OK

--

8

Repair the open in CKT 150 (BLK) between C102 terminal G and G102.

Is the repair complete?

--

System OK

--

9
  1. Disconnect the multifunction switch connector.
  2. Examine the terminals and the terminal sockets to make sure that they are clean and free of corrosion, and that no terminals are bent or broken.
  3. Re-connect the multifunction switch connector.

Is the repair complete?

--

System OK

Go to Step 10

10
  1. Disconnect the multifunction switch connector.
  2. Connect a test lamp from CKT 16 (PPL) at the multifunction switch connector terminal L to chassis ground.

Does the test lamp light?

--

Go to Step 11

Go to Step 12

11

Replace the multifunction switch.

Is the repair complete?

--

System OK

--

12

Connect a test lamp from terminal B5 of the turn/hazard flasher to chassis ground.

Does the test lamp light?

--

Go to Step 13

Go to Step 14

13

Repair the open in CKT 16 (PPL) between the turn/hazard flasher and the multifunction switch.

Is the repair complete?

--

System OK

--

14

Connect a test lamp from terminal B2 of the turn/hazard flasher to chassis ground.

Does the test lamp light?

--

Go to Step 15

Go to Step 16

15

Replace the turn/hazard flasher in the flasher/relay center.

Is the repair complete?

--

System OK

--

16

Locate and repair the open in CKT 1540 (ORN) between the IP fuse block and the turn/hazard flasher.

Is the repair complete?

--

System OK

--