Truck or trailer problem

[nap61]

I moved my 16' utility trailer that had been sitting up for about 2 years. The brakes on the rear axel kept locking. The move was about 1 mile. I had to back up to release the brake for a short distance. It did this 5 times in the mile. I parked the trailer and jacked up the rear. With the truck disconnected, I could easily turn the tire. When I connected the electrical plug, the wheele would lock. I have an '08 Titan without a brake controller (to my knowlege). This was the first time pulling the trailer with this truck. My S in L came over with his '05 2500 Chevy 4X4 (w/o a brake controller), connected the trailer and drove around the neighborhood with no problems. All the lights work properly with both trucks. Where (and how) should I start diagnosing the problem - the truck or the trailer?

Chris,
If I remember right, you have an '08 Titan and pull a lot of trailers. Have you ever had a similar prolem?

Norm

 

[deepNdirt]

have you checked for a bad relay in the truck panel?

 

[aczlan]

Have you ever towed this trailer with this truck?
I would put a meter on the brake pin and the 12 volt pin to check that they aren't swapped. Some manufacturer (Chevrolet?) has the pins (2 and 4 on this diagram) swapped in their factory plugs which would explain why it worked with the Chevrolet.

Aaron Z

 

[Diamondpilot]

Never a problem with my Titan but I do have a brake controller in it. Towed my 18' trailer with it about 100 miles just Friday moving to Pontiac's for a friends son.

As said before some wires are swapped. The Titan is wired from the factory, if yours is still factory, to industry standards. GM did flip flop some wires in the 2000's which made things tough.

If your truck is factory leave it alone and fix the wiring on the trailer.

Chris

 

[nap61]

Thanks for the replies.

Chris,
I pulled this trailer regularly with my '05 Chevy 1500 with no problems. The trailer has a 6 pin connector and the Chevy had a 7 pin plug/connector. My Titan has a 7 pin plug/connector. I used an adaptor to go from 6 to 7 pin ( the same adaptor). It worked on my Chevy and my sil's 2500 but not the Titan. I spoke with a ?mechanic? at the trailer dealer and he indicated there are two types of 6 to 7 pin adaptors. I may have the wrong adaptor for my Titan. Does that sound reasonable?

Norm

 

[VitaBene]

That is your problem, wrong adapter!

 

[Skyco]

Not necessarily wrong adapter, but could be. There are two
"standards" for 6 pin wiring, some adapters are made to let you swap two wires internally to allow for either "standard". BTDT

http://horsetrailerworld.com/home/wiring.asp

Scroll down to 6 pin- they show how +129(BLACK) and brakes(BLUE) are swapped on some trailers.

 

[Diamondpilot]

Yep, the adapter you have is the issue. If it were me I would cut the 6 pin end off and trade it for a yellow dog. When I got the dog home I would shoot it. Then I would put on a new 7 pin plug to the trailer.

Really though, no one uses 6 pins any more. They are a thing of the past.

As mentioned above many 6 pin to 7 pin adapters can be taken apart and there are two wires inside, usually red and blue, that can be easily swapped. All the other wires will be soldered but these two will have spade type connectors.

If not any trailer store will be able to set you up.

The issue is GM for some unknown reason decided to do there own thing in the late 90's early 2000's on wiring. They were different than the standard that Ford, Dodge, and all the imports followed. They finally got it right but its caused so much confusion just like you have had.

Chris

 

[Smallplot]

My question is why don't you have a brake controller? They are relatively inexpensive and pretty easy to install anymore with harness connectors. Just saying :confused2:

You have scientifically located the problem is with your truck, kinda. I would take apart the 6 pin connector on the trailer side and swap the two wires. there is a small phillips screw in the plug body which holds it together. If you can get that screw off it will take only a couple minutes to swap. If not easiest fix would be to get another plug from your favorite parts place and cut the old one off then reinstall the new one. This may take 20 min or 1/2 hour to do but is still an easy do-it-yourself repair.

From my experience make your own wiring diagram. Sketch what the truck plug looks like (the 6 pin) as looking straight down the connector on the male side (truck side). use a meter or test light and check each pin and label them in your diagram. Then use that diagram and check your female plug (trailer side) and make sure each wire is connected to the correct pin. After done, throw the diagram into the glove box, because if your old and forgetful like me, it may come in handy down the road.

 

[Soundguy]

yep.. my 2000 yukon, I had to get the 6 to 7 adapter that lets you swap a wire, otherwise the brakes lock.

for sure a wireing 'standard' issue

why call it a standard if they are all different..


soundguy