Electrical issues 04 Tahoe

[Tahoe-Lady]

I've been having some odd electrical issues with my 04 Tahoe for a few months now. It started with my remote start not working intermittently (especially when its cold) then I randomly hear bass coming from my subs when there's no music on and volume at zero (stops when stero is shut off) then my rear doors stopped unlocking with the power switch or fob, they auto lock when I shift to drive, but won't unlock. Now my check engine light is giving a P0141 code, 02 senor. I changed the sensor, next day same code, I changed it again, thinking it mightve been defective, but again same code. Im at a complete loss. Someone mentioned a bad ground, but theres like a bunch of different grounds, how would I figure this out? It all seemed to start happening a month or so (with the remote start) after I had my engine changed. This is a picture of one wire I found that seems like it could be bad, but I have no idea what it goes to. Its located off a wiring harness in the back pass side of the engine n feels like its bolted to the engine

[richard wysong]

it should be bolted to the back of the engine but its supposed to be an insulated wire and it looks like the insulations burned off it so Im betting the bad ground is elsewhere and its back feeding thru that wire causing the wire to overheat so check the main ground cable between the battery and the block to start. that wire may be the ground for the 02 sensor , you may want to open that harness up and make sure theres no other melted wires. ALLDATA has a ground location chart and wiring diagrams

[richard wysong]

some of your issues appear to be possibly BCM related possibly brought on by a ground issue

[Tahoe-Lady]

Thank you for the response. Ill get that from ALLDATA and see what I can find. Oh n that wire in the picture, that was supposed to be insulated, my engine had a small fire near one of the injectors, so im guessing that's how it melted. How would I go about replacing that one tho, as it comes out from inside that wiring harness? Would I just cut that open, find a good clean part and go from there?

[richard wysong]

yes cut the tape/convaluted tubing back enuff to make sure its just fire damage and not from the wire overheating. if its just fire damage the missing insulation doesn't matter as its a ground wire . check for any other damaged wires while you are there and tape it back up when you're done

[dna9656]

Again, any time an electrical problem gives bizarre symptoms suspect bad/dirty, rusted or otherwise FUBAR grounds.

[Tahoe-Lady]

What is FURBAR? I'm still new to the lingo lol 

[shakenfake]

fubar is ****ed up beyond all recognition

[Tahoe-Lady]

Ahhhhh ok, lol, I thought it was SOMETHING like that, but wasn't sure. Thank you. Im about to re-do that one ground in the picture. Hopefully this works

[It's Tim]

10 hours ago, Tahoe-Lady said:

Would I just cut that open, find a good clean part and go from there?

It's a good idea to always disconnect the vehicle battery before performing any electrical work. 

[richard wysong]

I would just open up the harness enuff to make sure the wire didn't overheat and if it looks ok  you could splice a new wire in or tape it  up  or shrink tube it or just leave it bare . the concern is that the wire is acting as a ground for something that it's not intended for and overheated melting the insulation and possibly damaging other wires in the harness. 

[richard wysong]

that would NOT be the bad ground if its melted further into the harness, to the contrary that ground would be ok trying to make up for another bad ground in the system such as the battery cable , body grounds etc

[Tahoe-Lady]

Yeah I did just change it n everything is still the same 

[richard wysong]

was it melted inside the harness or was it just fire damage? how far away are you from Beverly? I maybe able to help you look at it after the storm if you aren't far off and are open to that.  I think a lot of the problems other than the 02 sensor may be due to BCM problem. have you scanned the bcm as well as the engine or just read the codes?

[Tahoe-Lady]

No its not melted inside the harness, I was able to get some clean wire but couldn't get much wire out to work with. Im short and the truck is lifted lol. Beverly Mass is about an hour n a half away, I'm in Athol Mass. I havent scanned the BCM, I honestly didn't know you can. Ive pretty new at trying to fix things on my own. Do you need a special scan tool for that or will a regular one work?