Two hot wires in 7 pin harness

[wgordon]

Installed new Tekonsha P3 brake controller in my 2006 3500 SRW; went to RV dealer to pick up new Summit Ridge F32ES fifth wheel. Dealer installed hitch plus new wire harness in bed. Hooked up, plugged in trailer electrical and... brake controller says "Warning Overload No brakes" and all the trailer lights stay lit. Tech who installed new hitch and harness says he noticed two hot wires in the original bumper harness. Disconnected new harness and controller; still read voltage on two wires in bumper harness... one is the trailer hot wire (OK) and I'm not sure of the other. It was late, raining and getting dark so we left the RV at the dealer. Will try to get to the dealer on the morrow. Any ideas on the fault? The tech says he saw this same thing before on two Daimler/Chry products and the problem was with the "converter" in the truck??? Don't know what he's talking about! Thanks for any help.



WW

 

[jelag]

If your brake controller is under the dash and connected... it sends a signal down the brake wire... . looking to see of there are a set of axles back there... .

So your test light is finding the 12V hot lead and the signal from the brake controller on the brake circuit... .

Most brake controllers will give you some kind of statement when you first connect it..... if after pushing the pedal a couple of times or working the hand control it doesn't clear up... I'm guessing that your new trailer has a problem..... the guy that hauled it in usually tells the service manager of the problem but most of the don't care until it becomes a sold unit... .

Let me know if I'm right... ... ... .

 

[Hoefler]

I would hook it to another trailer and see if you get the same results. I agree with jelag, I have seen it before.

 

[wgordon]

... Let me know if I'm right... ... ... .

jelag

Couldn't get truck into dealer. So... checked 7-pin connector with multimeter. Battery and running light pins were hot. Determined from 2006 Service Manual what fuses effected trailer towing. Opened lid on Totally Integrated Power Module (TIPM) to check fuses. Fuze locations on inside of lid does not coincide with info in Service Manual. According to lid, position 15should contain a 20 amp fuse for trailer parking lights. Fuse position 15 was empty. Installed fuse. Again checked 7-pin connector; battery and running lights were still hot. As an aside, has your wife, when you couldn't find something in the refrigerator or cupboard, told you that "it's a bend over job"? Well, I bent over a little further and peered into the connector. At the very back was a jumper wire connecting the battery and running light leads. Now don't laugh... it ain't funny. Removed jumper; now only the battery lead is hot in the connector. Is it fixed? Hope so but won't know till I am able to hook-up tommorow. Only thing I can figure is that the first owner, unable to get running lights due the absence of a fuse, installed the jumper.

ww