Archived Any uniformity to trailer wiring?

[chef]

I've got a 99 2500. Went to pick up a trailer tonight to use this weekend and the brakes were locked up. I've got a Tekonsha Prodigy BC. At first I thought that since the colors of the wiring harness didn't match up to the body harness that they were backwards, so i used the pigtail that came with the BC and a spare body pigtail and matched colors, but then the BC wouldn't even power up, and the brakes were still locked up. If I unplug the harness at the bumper to the trailer, it rolls fine.



Hoping that there is some semblance of uniformity in the wiring and someone can point me in the right direction for finding a diagram featuring the factory 7 pin trailer plug at the bumper. That would REALLY help me out as I have LIMITED electrical skills and no telling how long it will take to figure out what each blade does on my own.



Have to get a good nights rest now, have a lot of work to do tomorrow.



EDIT:i contacted the trailer manuf. and found out that the plug is wired with the two wires mentioned below swapped, i picked up another, adjustable adapter, and will try it tonight. Was going to pick it up today but my buddy parked his truck in front of the trailer to keep it safe while he's at work. I'll be back home before i leave for the weekend so if it works I'll request this to be moved.



Thanks for the help.

 

[RustyJC]

What kind of trailer & connector - a gooseneck with a 6 pin round connector, or a gooseneck/5ver with the 7-pin flat blade Pollack-type connector that matches the factory 7-pin connector?



The Pollack-type 7-pin connector wiring standard is absolutely rigid and can be found HERE. Unfortunately, that's not the case with the 6 pin round connector frequently used on goosenecks. What often happens is the B+ (battery charging) lead and the trailer brake lead are reversed - when you plug in, you put +12VDC from the truck's battery charging circuit straight to the trailer's brakes, so they lock up. Most often, if you're using a 7-to-6 adapter, the adapter makes provision to swap these 2 wires when this happens.



Rusty

 

[chef]

that is exactly what happened, although it's just a bumper pull trailer. i'll break out the adapter and see if i can't figure out how to swap those two wires around.



halfway there!



that TSB is 94-97, are the pinouts still valid for a 99?

 

[RustyJC]

Yep, they were good on my 2002 when I put the additional 7-pin receptacle in the bed for the 5th wheel. I think the wiring colors (but not the pinouts) changed on the 3rd generation trucks.



On edit: That's why I said the Pollack-type 7-pin connector pinout convention is absolutely rigid. I've been pulling 5th wheels for a long time, and I'm a moderator over on iRV2.com, and I've never heard of anyone plugging any brand of 5th wheel into the factory connector of any brand of truck and having a pinout compatability problem with the Pollack-type 7-pin connector.



Rusty

 

[chef]

just wanted to make sure, thanks! i'll hit up the trailer company today and try to get a pinout for their 6 pin round connector and i should be straight.

 

[KB0OU]

Almost all 7 to 6 adapters come wired to put battery to the brakes, you have to swap the two leads, usually come with instructions to swap them on the package. Every time I got an adapter I had to change the wires.

 

[chef]

everything is hooked up and i'm about to leave.



thanks for the help, you saved me a lot of pointless time wasting with a test light.



move this whenever a mod gets a chance please!