GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2008 🢒 TopKick C-Series (Conventional) C4/C5 🢒 Brakes 🢒 Air Brakes 🢒 Air Dryer and/or Moisture Ejector Inoperative

Step

Action

Yes

No

1
  1. Turn the ignition switch to RUN
  2. Backprobe the inoperative component with a test lamp from terminal A to the chassis ground.

Did the test lamp light?

Go to Step  2

Go to Step  3

2

Backprobe the inoperative component with a test lamp from terminal B to B+.

Did the test lamp light?

Go to Step  4

Go to Step  5

3

Repair the open in CKT 341 (BRN) between S701 and the inoperative component.

Does the air dryer or the moisture ejector heater operate?

System OK

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4

Replace the inoperative component.

Does the air dryer or the moisture ejector heater operate?

System OK

--

5

Repair the open in CKT 150 (BLK) between the inoperative component and G404.

Does the air dryer or the moisture ejector heater operate?

System OK

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