If there is a thread that answers this, sorry I couldn't find it.

A fella just bought a used 08 3500 4x4 with the factory brake controller. He hooked it up and gets nothing. He knows nothing about them and doesn't know where to start. The lights do work. He's checked the fuses. They are good.

He was towing a gooseneck, so now he's looking to find another to rule out it being the trailer.

Does anyone have any suggestions on the fix or where to look?

Thanks.

Somebody? Figured if anybody would know this it'd be somebody here.

:)You have some wires under the hood that have to be connected. One is rolled up under the master cylinder and the other is rolled up between the fuse/relay box and the fender. (driver side) one of these powers the brake box and the other gives 12+ to the trailer. Find these wires and use a tester and you should be able to figure where they go. Its labeled in the fuse/relay box where they go. I hope this helps. :)

I have the same problem also, at least I think it's the same problem. My DIC gives a message " Service trailer brake system". If I hook up my trailer, all the lights work,but I have no brakes. And I don't get a "trailer connected" message either.

I've checked all the fuses (found one for the IBC and replaced it) and the wiring connection under the frame to the (???) module where some people say there is a corrosion problem. Mine is perfectly clean.

Would love to find out the solution so I don't have to pay the STEALER! I hate that.

There is a thread that covers this I will look for it. If the power wires are hooked up then you might need to wire in two brake magnets onto the trailer for the truck to sensor it has brakes. I just had to do this on one of my trailers. Look in towing sec, I think thats where I found it

To the OP, check stud #2 fuse underhood, 30 Amp.

Wildcatbrownhound< That is not exactly correct. The wire closest to the fender and the fuse box is for an AFTERMARKET brake controller. The other end is under the dash. The coiled wire under the master cylinder needs to be connected to the stud on the fusebox for BATTERY power to the trailer connector. For some reason I cannot post it (http://www.dieselplace.com/forum/showthread.php?t=327969) but here is the link. Unfortunately, neither of this helps his problem:(

:)You have some wires under the hood that have to be connected. One is rolled up under the master cylinder and the other is rolled up between the fuse/relay box and the fender. (driver side) one of these powers the brake box and the other gives 12+ to the trailer. Find these wires and use a tester and you should be able to figure where they go. Its labeled in the fuse/relay box where they go. I hope this helps. :)

So neither of the red wires in the engine compartment power the Chevy IBC, right? They power either 12V to the plug to the trailer, and/or an aftermarket brake controller.

So neither of the red wires in the engine compartment power the Chevy IBC, right? They power either 12V to the plug to the trailer, and/or an aftermarket brake controller.
No. The one already on stud #2 (factory connected) powers the brake controller.

So there is one wire to supply 12 V to the rear trailer connector, one to power the factory IBC, and one to power an aftermarket controller. Wait a minute, that's one wire too many. There's only 2 wires.

Ron,
The two wires are for BATTERY to the Trailer connector and a 12V feed into the cab for and AFTERMARKET brake controller.

Thanks for all the replies folks. Here is a quote from the guy with the problems...

"My '08 has factory installed trailer brakes...



The random thing of today is..... I drove it into madison without brakes.... Then I left madison and drove it to athens with out brakes.... I cut the truck off at the court house, went in got a tag came back out and fired the truck up,,,,, and it said Trailer Connected!! So now the brakes are working. So best I can figure is I have a loose ground or a short somewhere..... "

Page D-24 of the upfitter Manual clearly shows Stud #2 as the "High Current" source for the ITBC.:rolleyes:

the actual brake contoller is above the spare tire. the buttons on the lower kick panel is just a switch, the controller above the spare is what does all the sensing for braking the trailer. you could have a bad controller, i would think there would be some kind of code set in the brake controller the dealer should be able to read the code. hopefully this helps

Is there a way to remove the IBC and test it to see if working correctly? I guess, having a known good spare to plug into a faulty system would be great to help troubleshoot, but I don't have one.

What other technique is available?

No. The one already on stud #2 (factory connected) powers the brake controller.

I'm working on this, perhaps slowly. Are you trying to get me to understand that even if neither of the 2 red wires are connected, stud #2 is the one that powers the factory IBC? So, for instance, if the 30A fuse is blown (mine is), that is possibly the problem with my DIC message telling me to service the trailer brake system?

Or is it the case that stud #2 ONLY powers an aftermarket controller and the red wire needs to be hooked up for it to work?

Open the pdf in this link and read page #3.

http://www.dieselplace.com/forum/showpost.php?p=3119055&postcount=21

This tells how to install the charge wire and an aftermarket brake controller, BUT it also specifically tells you where the ITBC battery current comes from.









Which, ironically is ..................... Wait for it..........Wait for it............Stud #2 Fuse:p:

Or maybe this guy is onto something http://www.dieselplace.com/forum/showpost.php?p=2576005&postcount=85

Sometimes it just takes a while to sink in.

I looked at the stud#2 fuse in my truck several times and it looked fine. However, I decided a few minutes ago to to pull it anyway. It was very hard to get out. After pulling the clear covering, I could then see that, indeed, the fuse was blown. So it's off to the parts store tomorrow to get another 30amp fuse (maybe 2) and see if my problem is solved. Even if it isn't solved totally, gotta be closer to the final answer.

For any others who are having the problem where the DIC gives you a message that the trailer brake system needs to be serviced, an easy way to check the functioning of the fuse is to use a test light; put the point on the external terminal on the left - AKA stud#2 with the other end of the test light on ground. If no light, fuse is no good. This terminal should always be hot.

Appreciate your help and persistence.