Electric trailer brake wire always hot

[KKeen]

Hey Guys, great info, great web site. Have had TDR subcription for some time now,listening in almost always answers my questions. 1st post. I hooked my truck to a trailer with electric brakes for the 1st time, my truck has camper/trailer package but I have not put a control box in cab, When connection was made to trailer the brakes were locked, investigated to find 7 pin connector on truck has pin at 2:00 hot all the time. Red wire w/orange stripe, also hot under dash on electric brake factory 4 spade blue plug. Can't be normal, can it?

any help will be appreciated. I'm amazed at how well you guys know these trucks. Thanks in advanced.

 

[Peter Campbell]

Hi:

If it is the only always hot pin than that is normal. The service manual has a 40amp fused battery connection going to the trailer connector. The manual has it listed as red with a tan tracer but maybe the guy with the orange tracer was the low bidder that week. If you find 2 always hot connections then there is a problem on the truck. If that is the only hot line the last person to wire the trailer did not do it to standard. If you go to an RV or trailer place you can maybe find out what the standard pin- outs are and put it together right. That last guy may have done a "custom" job. Very common if adding the hitch and trailer wiring after the fact. Reference 1998 service manual section 8W-54

 

[Thomas]

Look at the cover on the 7 pin outlet at the receiver. You should find a pin-out molded into the cover.



Red/orange at four-pin electric brake controller provision socket under dash is fused (40 amp) source of B+.



It just might be that the wiring on the trailer that you hooked to isn't normal.

 

[JLinder]

I've been down this road...

First time I hooked my new Dodge up to one of Dad's trailers, brakes were lock as soon as we put the plug in the socket (didn't yet have a brake controller). Forgot about the problems, and borrowed one of dad's other trailers and blew the 40amp fuse in the engine compartment as soon as I plugged in. Got to checking the wiring on the plug and it didn't match the diagram that was on the socket door. Changed everything around and it works fine. Told Dad about it and he said two different neighbors (both have Dodge's) also couldn't get the wiring to work on his trailers. That made me think that Dodge had my plug wired incorrectly, so I checked it against a Pollak universal 7 pin wiring diagram. Guess what... It's correct. Why is his trailer wired different than that?



It's wired to work with the factory plug on his 2001 Ford PSD...

 

[Fuzz]

Think Jlinder is on the right track. On the y2k... the pin at 1 o'clockie

the first one to the right looking at the plug... is the fused B+ and the wire is RD/OR.



The wire at 11 o'clock or first one to the left is the one from the

Relay for the clearance lights.



Makes you think the trailer plug is wired wrong.

Here is a pretty good little book on wiring RV's



http:/www.rverscorner.com/ebooks/ebooks.html

Fuzz

 

[Archive]

You might find this site helpful.



http://www.marksrv.com/wiring.htm



Good luck.

Jim

 

[KKeen]

JDMoore, Thanks for the web site link, it was helpful. It looks like the truck and trailer might be wired differently. The trailer uses the blue wire for the elctric brakes and the red auxillary is not hooked up. According to the diagram on the web site the red is brakes, and the blue is auxillary. My truck is all factory wiring, but the trailer was borrowed from a Ford owner

I still find it strange that I would have a hot wire all the time on my plug. Maybe I'll go ahead and put a control box in my cab and see if I can get it straight. Thanks for your help.