Still having electrical issues.

[Devinj234]

Alright guys, I've been at this for about a year now with this electrical issue. Everything passing the bed of my truck and after that does not work, meaning nothing electrical in the rear is working. I took it to the dealer and they said about $2,000 and that wouldn't even guarantee a fix. I did have them use their scanner and this is what came up. About 2 pages of codes. I replaced the TIPM but that wasn't the issue so I am stuck once again with a truck that I have not been able to enjoy for almost a year.. Can anyone help??

 

[tron67j]

Sorry to hear of your problems.

Are you the original owner? If yes, has the truck ever been in a flood situation? Was it ever damaged in an accident? Have you had any other problems before this and it so, please list them out.

If you are not the original owner have you run a car fax report? How is the undercarriage and up under the dash and under your seats, is there rust around those areas and for the undercarriage not just small amount here or there but excessive covering a wide spectrum of surfaces.

Others might have more questions or ideas already, but this can help eliminate some possibilities.

Good luck on this.

 

[dsherman26]

Watch it be a single broken wire or a rusty body ground that supplies power to some things in the rear. Since one of the the codes is "lost communication with the BCM (body control module)", I'd start with trying to find out if the BCM is even getting power and CAN first. Dealer techs seem to be terrible at diagnosing anything electrical if goes beyond plugging in a scan tool. Some actual electrical troubleshooting is needed. I fixed the power mirrors on my Traverse that were not working after the dealer had it for two days and somehow decided it needed a new $1500 body control module, and insisted the blown mirror fuse I had found was good. I consulted the factory service manual wiring diagrams and found the dealer was full of it; the body control module didnt control the mirrors at all. I found the problem in 20 minutes using nothing but a digital multimeter: Mirror switch had a broken contact inside that caused a short circuit that blew the fuse. New $20 mirror switch and a fuse and the mirrors worked fine.

 

[Wild one]

Alright guys, I've been at this for about a year now with this electrical issue. Everything passing the bed of my truck and after that does not work, meaning nothing electrical in the rear is working. I took it to the dealer and they said about $2,000 and that wouldn't even guarantee a fix. I did have them use their scanner and this is what came up. About 2 pages of codes. I replaced the TIPM but that wasn't the issue so I am stuck once again with a truck that I have not been able to enjoy for almost a year.. Can anyone help??

Have you checked the big plug behind the drivers side front tire,sort of up in behind the wheel well liner for corrosion/bent pins /plugged in fully etc.

 

[markabby]

i knew someone who had a similar issue (different vehicle) they found out a mouse chewed wires that ran along the rocker panel. nothing was shorted, just no power from the chewed wires back.

 

[Devinj234]

i knew someone who had a similar issue (different vehicle) they found out a mouse chewed wires that ran along the rocker panel. nothing was shorted, just no power from the chewed wires back.

I wish it was that, but unfortunately it started after my friend tested the alternator by disconnection the battery while the truck was on which is NOT good for the electrical in these things.

 

[Devinj234]

Have you checked the big plug behind the drivers side front tire,sort of up in behind the wheel well liner for corrosion/bent pins /plugged in fully etc.

I have teared every single pin connector there is on this truck.. I cant find anything.

 

[Devinj234]

Sorry to hear of your problems.

Are you the original owner? If yes, has the truck ever been in a flood situation? Was it ever damaged in an accident? Have you had any other problems before this and it so, please list them out.

If you are not the original owner have you run a car fax report? How is the undercarriage and up under the dash and under your seats, is there rust around those areas and for the undercarriage not just small amount here or there but excessive covering a wide spectrum of surfaces.

Others might have more questions or ideas already, but this can help eliminate some possibilities.

Good luck on this.

well this all kind of started after taking it off road through mud and water so it has been through it. I am the second owner and when I bought the truck it was MINT. Clean report and everything.

 

[Devinj234]

Watch it be a single broken wire or a rusty body ground that supplies power to some things in the rear. Since one of the the codes is "lost communication with the BCM (body control module)", I'd start with trying to find out if the BCM is even getting power and CAN first. Dealer techs seem to be terrible at diagnosing anything electrical if goes beyond plugging in a scan tool. Some actual electrical troubleshooting is needed. I fixed the power mirrors on my Traverse that were not working after the dealer had it for two days and somehow decided it needed a new $1500 body control module, and insisted the blown mirror fuse I had found was good. I consulted the factory service manual wiring diagrams and found the dealer was full of it; the body control module didnt control the mirrors at all. I found the problem in 20 minutes using nothing but a digital multimeter: Mirror switch had a broken contact inside that caused a short circuit that blew the fuse. New $20 mirror switch and a fuse and the mirrors worked fine.

I have almost no experience dealing with such things. I'd need some help doing that. But i might try and diagnose it myself.

 

[dsherman26]

I wish it was that, but unfortunately it started after my friend tested the alternator by disconnection the battery while the truck was on which is NOT good for the electrical in these things.

Ooof. I cringe whenever somebody does that. Without the battery present to stabilize the alternator's output, it can go much higher than normal and cause damage. My 1977 MG Midget had factory electronic ignition, and there's a big warning label under the hood explicitly stating to never do this because it can fry the electronic ignition. Hopefully he didn't fry your BCM.

 

[tron67j]

Do you have a trailer connection? If so, did you check to see if anything there is working?

If it was immediate after off-roading my first thought is that something has cut through a wire loom somewhere. Your best bet is to check the entire wire harness for the rear section for any cuts or breaks. Run right to the fuse box, the immediacy would seem to point to a catastrophic failure. You can get a 12v testing pen for 10-30 bucks and check various points along the harness, make sure the lights are on and blinkers flashing to have a chance to find where power is interrupted.

Also, check the grounding points. And ensure harness in its entirety did not get yanked from fuse box. Weirder things have happened to me.

 

[Wild one]

I wish it was that, but unfortunately it started after my friend tested the alternator by disconnection the battery while the truck was on which is NOT good for the electrical in these things.

If you don't have a multi-meter to check the alternator,you can use a screwdriver/key ring anything metal etc. to check the alternator.Touch the back bearing of the alternator with a piece of metal,if it's charging,it'll have a fairly noticable magnetic field right around the bearing,that'll attract anything metal.
Seems like there's 2 sides to your story,1 it started having issues after you drove through mud,the other story seems to point towards your buddies alternator check,i'm guessing your issues started after you buried the truck,and your buddy decided to do the dumb alternator test.
One question for you,how many beers were involved that day,lol.
If you were mudding,start checking for broken wires,as mud weighes enough to hurt wire harnesses

 

[Devinj234]

If you don't have a multi-meter to check the alternator,you can use a screwdriver/key ring anything metal etc. to check the alternator.Touch the back bearing of the alternator with a piece of metal,if it's charging,it'll have a fairly noticable magnetic field right around the bearing,that'll attract anything metal.
Seems like there's 2 sides to your story,1 it started having issues after you drove through mud,the other story seems to point towards your buddies alternator check,i'm guessing your issues started after you buried the truck,and your buddy decided to do the dumb alternator test.
One question for you,how many beers were involved that day,lol.
If you were mudding,start checking for broken wires,as mud weighes enough to hurt wire harne

 

[sleepy hollow]

I assume you have checked the ground connection between the cab and the bed? On my 2007, I have had to lift up the bed to get to the evap hoses near the gas tank that are regularly chewed by mice and squirrels. I have also had mice camp in the engine bay and chew on three of my cars during the COVID nonsense. Made my wife's Mercedes put up a whole bunch of codes before I found the location of the mouse shindig under the battery tray. Chewed through an injector wire on the Ram which was quite the surprise when I went to run an errand.

Anyway, back to the gound wire to the cab, that needs to be disconnected when raising the bed. It is just a thought that perhaps it was something overlooked in your troubleshooting. Either it is corroded/frayed/chewed, or otherwise not so groundy.

 

[markabby]

i'd start at the beginning. Trace all the wires to the front, and check each one for voltage, maybe could be done at the fuse boxes, after the fuse. A good multimeter with sharp pointed leads is your friend.

if you find voltage after the fuses, then you're going to have to push a pointed lead into each wire and see if it's live or not.

if there's no power before a fuse...ugh....bigger problems. Now you'll have to check the main harness wires.

anyway, that's how i'd do it.