GMC Troubleshooting Questions? Ask a Mechanic for Answers
Which sub-model is this and what engine?
Check these fuses, the IGN A fuse, the IGN E fuse and the Crank fuse all in the underhood fuse block.
If the fuses are not named and have numbers instead they are 34, 22 and 17.
What do you mean "appear"? If you actually tested them then you would know. If you only looked to see if they were blown, test them.
is it an XL, XUV or no?
use a voltmeter and test the fuse while it's in it's spot and check both sides of the fuse, that is how you test both if the fuse has voltage to it and the fuse is ok and has voltage leaving it.
There should be no need to pull any fuses right now. If you don't have a voltmeter and 12 volt test light will also work.
Ok, I am going to give you a wiring diagram. Then I will guide you trough what to test next.
First off, hold you finger on the starter relay, #47 in the underhood fuse block and have someone turn the key to start. Can you feel the relay click?
If not, remove that relay and test all the spots in the socket for voltage (12 volts). One spot should be hot all the time and then an additional hot when the key is turned to start. Is that confirmed?
Actually the second test will be hot with the key on start and run, so check both
If the relay clicked and both spots are hot when I said, try a new relay and if that don't fix it we will test more.
I have to ask, when you tested those fuses, you had to have the key on run to test fuse 22 and the key on start to test fuse 17. did you?
That is exactly why you should be using a voltmeter or at least a 12 volt test light when checking fuses. An ohmmeter will only show you if the fuse is blown or not, it won't show you if the fuse has voltage to it and nowadays some fuses are fed by other fuses so it is a must to check for voltage.
What is a "nitheng" model?
When you checked for voltage to fuses 17 and 22 did you have the key on run or start?
Fuse 34 is hot all the time, fuse 17 is hot with the key on start and fuse 22 with the key on run or start.
Forget the sub-model, all of the wiring diagrams are most likely the same. Plus I did look it up for just the plain ole 4.2, no XL or XUV.
did you have the key on run or start when testing fuses 22 and 17?
The IGN A fuse feeds the crank #17 fuse. I don't recall you telling me the results of testing that fuse IGN A fuse.
Here is that wiring diagram showing how the IGN A fuse feeds the ignition switch and eventually that crank #17 fuse.
That fuse 22 is fed from the IGN B fuse #36 in the underhood fuse block.
And here are those wiring diagrams,
Are we done?