Just got my new 2008 3500HD with ITBC brake control.I cant get any elect to the trailor brake outlet. Help GBK

Have you activated the ITBC thru the DIC?
What do you mean by "no voltage"?
Does your trailer have all-electric or electric over hyd brakes?

search electric over hyd,but ive read you need to connect 2 electric brake magnets in line and the factory controller will work

On the '06 and earliers ones, there's a fuse taped to the brake controller harness that has to be swapped into the fuse panel under the hood. There's a dummy fuse in it's place.

Could the new models be similar? You have to "power up" the circuit first?

Mike P
06 DA CC DRW 2WD

the problem is that the new factory controlers dont see the electric over hyd pump,so to make it be seen you need to add 2 trailer magnets , ive called prodigy and there brake controler needs the same thing ,,i only realized this after i towed a 35' offshore boat and got to were i had to and thought the trailer brakes were bad ,just to find out they were never on ,because my prodigy brake controller never saw it,gm has such good brakes that it wasn't any problem ,but i'd like to have things right

the problem is that the new factory controlers dont see the electric over hyd pump,so to make it be seen you need to add 2 trailer magnets , ive called prodigy and there brake controler needs the same thing ,,i only realized this after i towed a 35' offshore boat and got to were i had to and thought the trailer brakes were bad ,just to find out they were never on ,because my prodigy brake controller never saw it,gm has such good brakes that it wasn't any problem ,but i'd like to have things right

anyone know how to wire these magnets? i want to try this before i go with the aftermarket. I cant find anyone who knows how to wire them in. i have the magnets just trying to figure how to wire it.

Derek

Hook a pigtail of each magnet in parallel with the blue brake wire of your trailer brakes and the other pigtail of each magnet to trailer ground. BTW I thought you only needed to use one magnet but I may be wrong. My knowledge comes from an RV forum (rv.net.com).
Dave

anyone know how to wire these magnets? i want to try this before i go with the aftermarket. I cant find anyone who knows how to wire them in. i have the magnets just trying to figure how to wire it.

Derek
wire the two magnet between blue and white wire. each magnet draws 3.2 ohm at 35 watt each. same as one beake axle.

Just got my new 2008 3500HD with ITBC brake control.I cant get any elect to the trailor brake outlet. Help GBK
found my problem .won,t work with elect. over hyd. I installed two brake magnets but didn,t work all the time .check with your gm dealer service bulletin x115. I had to run a new blue wire from under fuse box to 7 wire plug to the back. with a prodigy brake control, work now .GBK

found my problem .won,t work with elect. over hyd. I installed two brake magnets but didn,t work all the time .check with your gm dealer service bulletin x115. I had to run a new blue wire from under fuse box to 7 wire plug to the back. with a prodigy brake control, work now .GBK

I had the same problem. When I went to pick up my trailer I was confident I could use the IBC because the trailer brake actuator manufacturer (Carlisle) had tested it and said it worked fine. When I got to my RV dealer and hooked up I had no brakes. Called Carlisle and they had a different story then. Since GM would not endorse the controller for elec/hyd disc brakes they cited liability reasons to pull the information. Said it would work but they wouldn't tell me how ... Censored.

RV dealer installed new Tekonsha P3 controller and still no brakes. They would not let me in the shop. They messed around and determined they needed a wire from P3 controller to trailer plug. They ran a 14ga wire with no loom or clips. Just the wire waiting to short out from wear. They did not run it all the way to the plug. Just tapped into the harness near the axle. That got me home but I have to redo that wire properly. GM recommends 12 gauge. Carlisle says minimum of 12ga and preferably 10 gauge. What I need to know is where that wire runs from. I know it goes back to the truck mounted trailer plug. What gauge wire is used for brake wire in optional 5th wheel wiring harness? Does that wire need to be upgraded too?

This little fiasco has cost me $500 so far not including the cost of the IBC. I knew going in that the IBC was only for electric brakes but did not figure that GM would exclude the use of a 3rd party controller in their wirng harness. Just another gotcha. I hope yours is working great now.

Just did the exact same thing with my '08. I have the Prodigy controller. RV dealer took truck to Chevy dealer up the road and had them install a wire between the blue wire, as it comes out of the back of the Prodigy to a point in the wiring harness at the back of the truck to the blue wire back there. These were not bridged connections. The blue wires at the Prodigy as well as the blue wire in the wiring harness near the plugs were cut and this new blue wire was installed between these two points. Controller works great now. Chevy dealer did use wire loom and tie-wrapped the loomed wire all the way back along the truck frame. They did a professional job in my opinion.

Moved so others can benefit from this knowledge.

Just did the exact same thing with my '08. I have the Prodigy controller. RV dealer took truck to Chevy dealer up the road and had them install a wire between the blue wire, as it comes out of the back of the Prodigy to a point in the wiring harness at the back of the truck to the blue wire back there. These were not bridged connections. The blue wires at the Prodigy as well as the blue wire in the wiring harness near the plugs were cut and this new blue wire was installed between these two points. Controller works great now. Chevy dealer did use wire loom and tie-wrapped the loomed wire all the way back along the truck frame. They did a professional job in my opinion.

Hey RV Guy,
Thanks for the information on the wiring for the Prodigy. I am right in the middle of re-doing that job now. Came in to see if there was an new info on the subject. My "new" blue wire is run the same as yours, just NOT professionally done and wrong gauge wire. I found #10 in white and #12 in blue. Decided to stay with the #12 blue - meets GM spec and no confusion with color.

There is an IBC block bolted to the frame in the wheel well on the driver's side. I am assuming this new wire by-passes what is going on in that black box.

Now I need to find a good place to mount the P3 on the dash. It is supposed to be horizontal and in the plane of travel with no tilt or yaw to the side. Not doing this correctly will affect the decelrometer. It appears I will have to find or fabricate my own bracket. And I have two holes in the front of the dash to repair. Actually 3. Seems the guy that installed it needed 3 holes for two screws.

I sure wish GM had thought this out better. They should accommodate Hyd/Disc brakes in their IBC.