Trailer wiring.

[O2bsmitty]

I have a trailer for the sxs that I normally pull locally with my ford (2008) and all lights, brakes, etc work as they should. Hooked it to my gmc (2022) and when I back put it in reverse it locks the trailer brakes. Anybody ran into this issue? It is wired per the diagram. If this isn’t the right place to ask this sorry.

 

[Admin]

 

[O2bsmitty]

I have a trailer for the sxs that I normally pull locally with my ford (2008) and all lights, brakes, etc work as they should. Hooked it to my gmc (2022) and when I back put it in reverse it locks the trailer brakes. Anybody ran into this issue? It is wired per the diagram. If this isn’t the right place to ask this sorry.

I plan on putting the wife in the seat and test the truck plug but just wandering if anyone has had same issues

 

[JenElio]

I have a trailer for the sxs that I normally pull locally with my ford (2008) and all lights, brakes, etc work as they should. Hooked it to my gmc (2022) and when I back put it in reverse it locks the trailer brakes. Anybody ran into this issue? It is wired per the diagram. If this isn’t the right place to ask this sorry.

Check to make sure the rear back up sensor setting is off. I don't know what the technical term is for it but the button that makes it stop beeping when you're backing up and getting close to an object. My buddy has a newer RAM and it did the same thing once.

 

[Remington]

I have a trailer for the sxs that I normally pull locally with my ford (2008) and all lights, brakes, etc work as they should. Hooked it to my gmc (2022) and when I back put it in reverse it locks the trailer brakes. Anybody ran into this issue? It is wired per the diagram. If this isn’t the right place to ask this sorry.

I have a 24’ GMC HD with the trailer towing tech package. The things are touchy if things aren't wired right or if u have a ground issue with the trailer etc.

I use to work on Car Hurlers alot in my previous job. So we need to start with some simple things to cross off your list first. U said everything worked as it should, lights brakes etc. with the other truck correct?
If so, and your having trouble with the new truck, you beed to verify wiring from the 7pin.
Nice thing about the GMC’s they have a diagram on the 7pin cover to verify what pic does what. So get yourself a test light. Have someone sit in the truck and test each corresponding pin to each action for the trailer. This will verify id your male 7pin connector to your truck is wired correctly.
Do this check and report back. Dont forget to tag me so i get a notice😁

 

[WagginTail]

I just had this issue with a trailer but in theory it would happen with any tow vehicle. In the trailer plug the wire for the brakes had 2 strands of wire sticking out and touching the terminal for the reverse lights. So when we put the truck in reverse it would send power to the brakes. Just something to check. I suppose same thing could happen in the plug on the truck as well.

 

[Remington]

I just had this issue with a trailer but in theory it would happen with any tow vehicle. In the trailer plug the wire for the brakes had 2 strands of wire sticking out and touching the terminal for the reverse lights. So when we put the truck in reverse it would send power to the brakes. Just something to check. I suppose same thing could happen in the plug on the truck as well.

Good points. But lets not make him jump all over before he verifies a few simple things first or he will go🤯

 

[Dirtstiffs-1000]

@O2bsmitty

7 pin trailer plug tester
4 wire plug tester
There's a ton of these type of trailer plug testers available to verify your tow unit wiring, then align - match your trailer wires to it.
Easy way to troubleshoot or maintenance check wiring..
Some newer vehicles have a trailer break - connection detect mode, too.
Good luck

 

[O2bsmitty]

Check to make sure the rear back up sensor setting is off. I don't know what the technical term is for it but the button that makes it stop beeping when you're backing up and getting close to an object. My buddy has a newer RAM and it did the same thing once.

I will try shutting that off. Thanks.

I have a 24’ GMC HD with the trailer towing tech package. The things are touchy if things aren't wired right or if u have a ground issue with the trailer etc.

I use to work on Car Hurlers alot in my previous job. So we need to start with some simple things to cross off your list first. U said everything worked as it should, lights brakes etc. with the other truck correct?
If so, and your having trouble with the new truck, you beed to verify wiring from the 7pin.
Nice thing about the GMC’s they have a diagram on the 7pin cover to verify what pic does what. So get yourself a test light. Have someone sit in the truck and test each corresponding pin to each action for the trailer. This will verify id your male 7pin connector to your truck is wired correctly.
Do this check and report back. Dont forget to tag me so i get a notice😁

thanks for the info. Haven’t had time this morning to do anything yet so going to do an early lunch then planning on tackling it. I will get back to ya hopefully with its fixed. Not my luck. lol.

 

[O2bsmitty]

I have a 24’ GMC HD with the trailer towing tech package. The things are touchy if things aren't wired right or if u have a ground issue with the trailer etc.

I use to work on Car Hurlers alot in my previous job. So we need to start with some simple things to cross off your list first. U said everything worked as it should, lights brakes etc. with the other truck correct?
If so, and your having trouble with the new truck, you beed to verify wiring from the 7pin.
Nice thing about the GMC’s they have a diagram on the 7pin cover to verify what pic does what. So get yourself a test light. Have someone sit in the truck and test each corresponding pin to each action for the trailer. This will verify id your male 7pin connector to your truck is wired correctly.
Do this check and report back. Dont forget to tag me so i get a notice😁

Ok. After checking truck it was fine and instead of fighting it I decided to start over. I ignored the wiring diagram for the plug and wired a new 7 pin to match the truck diagram and believe it or not it worked. Now if I hook to the ford I don’t know lol. The gmc and trailer are ready to head to Arkansas. Thanks again for all the help.

 

[Remington]

Ok. After checking truck it was fine and instead of fighting it I decided to start over. I ignored the wiring diagram for the plug and wired a new 7 pin to match the truck diagram and believe it or not it worked. Now if I hook to the ford I don’t know lol. The gmc and trailer are ready to head to Arkansas. Thanks again for all the help.

Sorry for the late response. Ben resting. Had a procedure earlier in the week and needing rest here and there.

Anyway. Nice job👍🏻 glad u got it fixed. Process of elimination. As long as all worked according to the truck set up as it should, move on to the next and it looks like you did with success. Have fun on your trip

 

[O2bsmitty]

@O2bsmitty

7 pin trailer plug tester
4 wire plug tester
There's a ton of these type of trailer plug testers available to verify your tow unit wiring, then align - match your trailer wires to it.
Easy way to troubleshoot or maintenance check wiring..
Some newer vehicles have a trailer break - connection detect mode, too.
Good luck

I realize this but I just didn’t think or understand why each vehicle would be different. This is exactly what I ended up doing but it works on my gmc but don’t know if it will for my ford.

 

[O2bsmitty]

Sorry for the late response. Ben resting. Had a procedure earlier in the week and needing rest here and there.

Anyway. Nice job👍🏻 glad u got it fixed. Process of elimination. As long as all worked according to the truck set up as it should, move on to the next and it looks like you did with success. Have fun on your trip

No problem. I appreciate the help. This group is a bunch of good people. Hope all is well. Thanks again.

 

[O2bsmitty]

Ok now that I mentioned Arkansas. We are heading to ozark area. Staying at turner bend. Does anyone have any can’t miss points of interest as far as scenic places. We are old and don’t mind some technical trails and will bounce ( a little) but we don’t want to worry about breaking like we got into at tacket creek in Tennessee. That’s a whole other story.

 

[WagginTail]

I realize this but I just didn’t think or understand why each vehicle would be different. This is exactly what I ended up doing but it works on my gmc but don’t know if it will for my ford.

I think there are 3 different styles of trailer plugs that are all the same size 7 pin but the wires are in different order. Why the trailer industry did that I don't know but it can be confusing. Just rewire your ford plug the same and you'll be good to go

 

[NewHere2]

Typically the battery charge wire and the trailer brake wire are changed around.