[ch0bby]

First off, new to posting here but LONG time fan of the wealth of information found within this site. That being said, I hope I'm doing this in the correct section...

2011 Colorado, 5.3L 4x4. I'm having some weird electrical issues and am baffled at what could be the cause. Occasionally, the gear indicator light on the dash "drops out" when I shift to drive. If I notice this, I can shift back to neutral (or any other gear) and it pops back on and I can drive as normal... except when this happens the truck shifts hard... especially from 1st to 2nd. The rest of the gears aren't as noticeable.

A second issue that may or may not be related, is sometimes (independent of the gear indicator light issue) when I cut off the ignition and open the door I get a chime from some reason. The chime is very similar (if not the same) as if I left the headlights on, even though they switch is in auto. I feel like the truck is trying to "tell me something" but I don't know what.

Anyone ever experienced either of these issues? Where would I even begin troubleshooting besides the obvious of looking for broken/frayed wiring (which I have found none)??

 

[hammer mechanic]

Check you ground at the rt and left aprons first. Search for write up on the forum.

 

[ch0bby]

That was my initial suspicion. I removed (cut off) the splice packs and tipped each wire with solder and installed them into a ground bar/terminal... then grounded each ground bar back to the respective fender side wall as well as the battery negative cable mounted to the body behind the base of the battery. I SHOULD not have ground issues with any of the wires that used to be in the splice packs.

On that note. When checking the voltage on the ground.... 0.000 with the key off and turned to accessory... 0.024 with the key in run, and 0.037 with the engine running. Are these normal numbers?

 

[ch0bby]

Any other ideas?

 

[JBSavvs]

Hey there ch0bby, I own the same truck...09'
I had very similar problem, transmission shifting hard from 1st to 2nd, gauge cluster wigging out from time to time. After 4 hours of searching, Found a rubbed out comm. wire (Comm. Bus A to be exact) in the engine compartment up against the frame causing the problem. Repaired the wire, wrapped it with a piece rubber hose, never had that issue again. Will send a pic if I can figure out how...Lol

 

[ch0bby]

A picture and location would be great. I'm unsure if it will apply as I have actually replaced the main wire loom/harness (engine, transmission, etc)... but it is possible that if it's a wire in an old loom then something I could look at.
So far I have replaced the main loom/harness (part number 20820222), "deleted" both ground splice packs in the engine compartment into ground bars/terminals (and run 12g primary wire from each ground bar back to the battery negative), cleaned the paint from beneath the ring terminals on the grounds behind the battery base, below the driver seat, passenger seat, and center console.

Again, the transmission only shifts hard on the rare occasion that my shift indicator (below the "D" on the dash) disappears. When that happens, I can shift gears out of drive, then back to drive and the indicator light comes back... but for the duration of that drive the transmission will shift hard.

Also, the annoying warning chime when I shut off the engine/ignition. This is much more common and doesn't seem to have any rhyme or reason. It may do it when I shut off the ignition, it may do it when I remove the key or open the door... but it does it often. Fast paced warning chime, similar to when you leave the lights on, only they aren't on.

Another thing I've noted, when I crank the truck (before putting the truck in gear) my parking lights always come on... whether night or full sun. I'm not sure if this is a normal behavior. The light sensor in the dash seems to work fine judging by the headlights coming on/going off when they need to. I think at this point I'm just paranoid of anything potentially indicating an electrical problem. This issue is driving me nuts.

One question for the group... are there any other ground splice packs or common grounds anywhere? I've read conflicting info that there might be a third splice pack, possibly in/below the dash or near the ignition.. but I've yet to find it?