1997 GMC K2500 Suburban 7.4L - interior electrical issue(s)

[MartyW]

Hi all,

Everything was ok electrically until a few days ago, and then the following items all became inoperative at (I think) the same time. I've checked all fuses that appear (from owners manual descriptions) to have anything to do with any of the problems, and all the fuses I've checked look good.

.) Interior dome light inop when opening any door (all door switches were fine a few days ago).
Dome light still works ok with roller manual switch, just not with the door switches.

.) Power door locks inop (I can hear relay click in left side of dash but locks don't move).

.) Remote keyless entry inop (doesn't work on any function, lock or unlock).

Everything else seems to be ok, exterior lights, DRL, A/C, blower fan, cruise control.

Any ideas from you who are familiar with the wiring & current flow in these trucks/burbs?

Many thanks in advance,
Marty

 

[twomanymontes]

Without a wiring diagram I'm not 100% sure, But it sounds like you have a bad ground. I believe the ground is under the dash, on the driver side above the parking brake. Mine broke years ago and messed up a few things, don't remember what other than the door locks

 

[MartyW]

Thanks twomanymontes. I've looked at several wiring diagrams that I found online. None of the diagrams were complete but they all had portions that covered the items that no longer work in my burb. All the power seems to start with fuses 3, 4 and/or 13, which all look good. I'm not super knowledgeable at reading the diagrams but it appears to me that the power is probably getting to the units, as depicted by red or orange lines going from the fuses to the instruments, and then black wires in the diagram I believe are the grounds (not sure) that go from the other side of the items to common ground points. If this assumption is correct then the bad ground suggestion seems to hit the jackpot. Can you remember how you discovered your broken ground and what could have caused the break? I'll sure take a look under the dash to see if I can spot anything. Thanks.

 

[MartyW]

Issue resolved. Pwr-Accy fuse (fuse "A" in LH I/P fuse box) was not making correct contact. Fuse was ok when pulled but fuse box prongs had been previously bent to not make proper contact with both legs of the fuse. Problem corrected. We've had this vehicle only a few months, and its amazing that it worked this long.