Sorry if this has been covered, I searched and did not find my answer.


Truck: 2004 Silverado 2500HD Duramax w/tow pkg
Controller: Tekonsha Prodigy w/GM connector (new in box).
Trailer: 1994 Aljo 27'

Installed the controller and plugged in connector(s) to truck and controller as indicated. Plug in trailer connector, have lights, signals, brake lights etc but no brake signal sent to electric brakes.

I get the "nc" (no connection) lights on controller. I've tried installing the 40a fuse that came with the stock GM controller harness in "stud 1" position as suggested with the stock harness, no difference.

The trailer brakes worked fine with my old tow vehicle, 85 F250 with hydraulic actuated controller.

Called Tekonsha tech help. All the gal could tell me was the controller must detect a ground from the magnets before it will indicate as "connected". When I mentioned the brakes worked with an older controller, she said the Prodigy is "more sensitive" to the "ground signal". WTF?


At the truck trailer connector, I have connected a 12v bulb across from the ground pin to the brake pin, still no connection. I even jumped directly from ground to brake pin, no change.


Pulled truck trailer connector, looks good, brake and ground going to proper pins etc...

Can anyone suggest a plan to track down the problem?

Please help me slow down! <G>

David Jones

Are you sure your trailer is wired to code? For some reason people like to wire the brake wire to the center pin which is not correct.


Put a test light on the blue wire coming out of the brake control right at the brake control. The no connection should go away and the light should light up when you apply the brakes.


If all is well there you should do the same at the rear plug on the truck.

Under the fuse center under the hood there is a connector where the wire coming from inside the cab connects to the wire going to the back of the truck. You could check to make sure that is connected properly. It would also be a good place to check with a test light to see where your problems are. It will be a blue wire. If you have the factory tow package it should be connected. If you don't that might be your problem,

Are you sure your trailer is wired to code? For some reason people like to wire the brake wire to the center pin which is not correct.


Yes, it's standard and is the same as the truck connector.


Put a test light on the blue wire coming out of the brake control right at the brake control. The no connection should go away and the light should light up when you apply the brakes.


If all is well there you should do the same at the rear plug on the truck.


Did that, stuck a small wire into the connector at the rear of the Prodigy. Activated the manual lever, I light the bulb, but still get a "nc" and "sh" flashing. (owners manual says some test lights will give a "SH" readout)



Under the fuse center under the hood there is a connector where the wire coming from inside the cab connects to the wire going to the back of the truck. You could check to make sure that is connected properly. It would also be a good place to check with a test light to see where your problems are. It will be a blue wire. If you have the factory tow package it should be connected. If you don't that might be your problem,





It too is connected, guess I should probe into that wire to see if it's getting voltage there?


Did that, lights the bulb, but still nothing at the rear connector.


Thanks


DJ

If it lights the bulb at the controller then you need to find out where you are losing your connection. Go to that joiner, triple check that you have the right terminal at the back.


It sounds like the problem is in the truck.


For intrest sake I would hook up a known good truck to the trailer and make sure all the brakes are working. There could be a few bad wires and maybe only 1 or 2 brakes is working causing not enough resistance for the brake controller to see it.

I have the same box. The wiring was a little different on the GM side of things in the 03-04 model year. If you got the adapter that you buy in addition to the controller you might have the wrong model year adapter. I noticed that a wire switched position when I compared the two adapters at the store.


Just a thought.

I don't think that is the cause but its worth looking into.


http://dieselplace.com/forum/forum_posts.asp?TID=7718&PN=1

I don't think that is the cause but its worth looking into.


http://dieselplace.com/forum/forum_posts.asp?TID=7718&PN=1





Yes, I've seen that post. There is a tech bulletin on the diff between 02 to 03/04. I had really hoped that was the problem, but not to be, I have the "updated" wiring.


http://tekonsha.com/files/Product%20Bulletin%20-%2020020013.pdf


David
Edited by: IdaSpode

Did you do any more diagnosis?

Did you do any more diagnosis?


Nothing yesterday, busy putting out other fires. <G> I need to drop in to the dealer tomorrow on another matter, I'll see if I can pick a tech's brain about the issue.


Thanks for the interest, I'll be sure to post if/when I come up with an answer or solution.


David

Which brake controller? I have the 8 brake model and I used the GM pigtail that came with my truck. Just make sure you wired it right. Look at the stickys that were on the GM pigtail and make sure that you just attached the right wires. Only issue I had was the trailer's plug got some nasty muck in it driving the Alcan highway.

Did you do any more diagnosis?


Just to eliminate any issues with the controller, I disconnected the underhood connection and put 12v to the downstream wire, got nothing at the 7-pin.


Okay, start tracing the bundle from the front to the rear to see where any other connections might be, or places open to damage. Hmmm, big pile of spaghetti starting from the front, let's go to the rear.


I'd already pulled apart the 7-pin receptacle, all was well in there, but I neglected to inspect the other end of that pigtail, where the connection to the truck wiring is made.


I pulled it apart. Bingo...


One of the blade connectors on the truck side connector was not pushed all the way into it's slot. I got it in far enough for it to work but it wasn't extended quite as far as the others. It may have not been perfectly aligned and been pushed out when the plug was first pushed in the the socket during assembly. I plan to hit the dealership to have them fix it correctly, to my satisfaction. If it were just a light, I'd not worry much, leave it as is but no sense in taking a chance with the brakes going out unexpectedly.


I hooked up truck to trailer and all is right with the world, works as it should.


Don't ya just love crawling under your brand new $38K vehicle to fix some stupid little screw up? In the beginning I was fixated on the trailer, assuming the truck was alright. Then I fixated on the controller. Now it's easy to see where I should have started, verify you have continuity, duh...


This is my first diesel and my first experience here. It's been a good one, thanks to those who helped. Hopefully the next time I post, it will be to tell you how I'm getting 27mpg towing a bumper pull trailer at 23,000 lbs uphill in overdrive on leftover Brylcreem and bacon grease using a chip I made myself out of green keys and K&N filter parts...


Happy towin'


DJ