Hey all,

Help me please if you can

I have a 2005 Excursion XLT V10, and I tow a travel trailer with electric brakes. I purchased a Pod trailer brake controller along with the harness connector from etrailer last year. Installation was easy, and the connector fit correctly to the truck and to the new controller. Without hooking up the trailer, I thought the controller would show some signs of life just driving around, but no. Months later, I hooked up my trailer to find the brakes don't work, and still no signs of life from the new controller. I think the controller should light up whenever the truck is driving whether or not the trailer is hooked up. Is this true?

I guess the question is: How do I determine the problem? It could be dead wiring in the truck, bad harness connector, or faulty controller. I have a volt meter, and could test for power at the connections, but I don't know how these things are supposed to work.

 

Well for starters that harness should tie into a fuse somewhere IIRC. I'd start with that and see if the fuse is popped.

For clarification - you installed the controller with the stock harness inside the dash, correct? Reason I ask is there's an awful lot of sharp edges and such back there - it's a possibility the harness is chaffed or a wire is frayed/broken for the OEM harness. With the controller showing zero activity, I'd start there or the associated fuse.

As far as I know just winging it, checking for power and ground in the vehicle-side connector should show whether or not the truck harness is getting power. However I have NO idea which wires/prongs to probe other than the usual red/black power/ground. I imagine voltage should read between 11.5 and 14.2.

My Prodigy shows signs of life without a trailer hooked up, and if I actuate the manual brake lever I get a big 'nC' on the screen indicating no connection. The other level controls and such also make the screen work. If you aren't getting any of that with yours, assuming it has these features, then I'd suspect power to the controller first.

@WE3ZS, @pirate4x4_camo - y'all have any ideas? Tom since you're the towing guru and pirate because you have a scary stupid amount of knowledge on random things...

 

Yes. I bought the adapter harness to plug into the stock harness, and everything there looked to be in good shape.

A fair question. I did check all of the fuses in the panel under the steering wheel. All fuses were good.

I'm going to check for voltage on the truck harness (4 wires) and see what I get. I'll also check continuity in the adapter harness. I could put voltage to the controller if I knew which wire.

 

The fuses for the trailering power are under the hood.............I think.
My '05 V-10 XLT had all of the fuses in place when I bought it at 65k miles, but the previous owner (Uncle Sam) had done some towing with it. I have read where some others didn't have the towing fuses in place from the factory, they should be identified in the Owner's Manual, but I don't have a manual and I'm 20 miles away from my EX to check for you, hopefully someone else can chime in with that info.
I wonder if the fuses present/missing is associated with the factory "trailer towing" package? Since all EXs came with the rear hitch as a safety item and they all had the same sized trans cooler (for their particular engine, 7.3 was smallest, then V-10/V-8 and 6.0 the largest) and the springs were all the same with or without the tow option. Maybe the option just gave you the bigger mirrors and a couple of fuses?

 

OK so I put my voltmeter on it and found that it is getting power. The 4 wires leading to the controller are black(12v), white(gnd), red(brake pedal), and blue(brake volts to the trailer). I found that it is getting power back to the 7 pin connector at the rear bumper, too, and by all rights, should be powering the brakes. The unit is not responding because apparently, the trailer has to be properly hooked up for anything to work. I do not have the trailer with me today to check, but I'm thinking the truck and controller are alright. Next will be to check the trailer brake wiring for ground short, 7 pin connector plug for corrosion (likely), or maybe a broken wire going to the brakes. We'll see.

Anyway, thanks for trying to help. I'm glad the Ex is OK, and also that I didn't replace a perfectly good controller over some nasty trailer wiring. Should have looked for that first, but you've got to start somewhere.

 

How did you confirm continuity from the controller to the bottom rt pin of the 7 way?

On another note I'm 99% sure on the 05's the fuse for the keyed on 12v power to the rear 7 way (top rt terminal) is under dash on bottom row 2nd from left. Jcase fuse 40 amp.

 

Confirm the truck is known good,
Turn up the power on the controller, and tape the manual lever over to send full power back. Probe the bottom rt terminal, you should have power there. Once you do, plug in the trailer and now test the trailer.

Go under the trailer behind one of the wheels. Use an old school finger poker testlight, ground it to good metal and probe either of the two wires going to the brake plate.

Once you've determined which of the two wires are hot or power, shave off a little insulation on the other wire. No hook your ground to that exposed copper and probe the other hot wire.

If it lights up, you've now confirmed you have a good ground and power feeding the brake. If it doesn't light up, you've confirmed you have good power but not a good ground.

If you never had power on either of the two wires, work your way forward until you find the bad connection.

Note: you can test all the previous by using a battery at the front of the trailer and no truck.
Ground the negative to the trailer frame and supply 12v to the bottom left terminal as you look at the face of the 7 way.