GMC Troubleshooting Questions? Ask a Mechanic for Answers
Hi there, I am Cam. There is no way to tell what the issue is with out testing.
The test I would do is this. Open the door and use a screwdriver to trigger the latch so the truck thinks the door is closed. Open the hood and remove the cover for the fuse block. Take the meter and set it on direct current amps. Remove only the negative battery cable. If you have two batteries, remove both cables from the other battery. Get a 10 amp fuse and for a moment, connect the battery cable to the battery using the fuse in between. If that you does not blow, it is safe to proceed with the rest of the test. Place the positive lead of the meter on the negative battery cable itself. Place The negative lead of the meter into the negative battery post or terminal. Your meter should start reading a drain and it may be as high as 5 A. Wait 10 minutes for the reading to settle down. Optimum reading is 0.030 A. Start removing fuses one at a time and watch the reading. Remove every fuse and record the fuse or fuses that drop the drain below 0.030 A. Be sure to remove the abuses in every fuse block.