GMC Troubleshooting Questions? Ask a Mechanic for Answers
Hi there, I am Cam. Can I get your name please? Also can you tell me what engine is in your truck and the battery, its brand new today or was new then?
No problem Paul. Is there a remote starter install on the truck Paul?
TEh jiggling of the key suggests a bad connection in the ignition switch or around there and with the location of most added systems, the movement could cause this. I have one test. Do you have a volt meter?
Pop the tilt lever out and take the lower trim of the column off. With your multimeter set to DC volts, place the red lead on the red wire. With the switch turned on, test the other leads with the black wire. Record the reading and let me know what those are. Repeat the test on the red/white wire. Let me know the results.
Pop tilt lever out and lower trim pops down. Also remove the left fender brace and look in the area under the fuse block under the hood.
With the key on, those are horrible. They should be nearly 0. That means that over the orange, 10.5 of 12V is being lost. Those results tell me you need a new ignition switch. See the attached document. The switch is actually very cheap, 40$ or so from GM.
Yes that is incorrect. You need to back probe with the connector in and the key on.
No problem. its all good.
That tells me either the headlight switch is on, there is a short or there is a remote starter in the system.