What adapter for Prodigy P3 & GMC?

Not familiar with Prodigy P3 but my P2 is connected to my Chevy with an available pig tail to a plug under dash. Factory brake controllers were unheard of those days. If your '12 GMC comes with factory towing package, there must be a plug somewhere under dash. Call Prodigy's customer service and they probably can rush you one of those harnesses. If not, hardwiring these controller to the brake light circuit is relatively easy. Even I can do it.

If it has the 7-pin connector under the bumper, it likely will have an oem supplied connector/adapter in the glove box. With Ford these oem connectors need to be hard wired to the controller, but very easy to do, especially for an EE. :)

Jerry

I've used my P2 on 3 different tow vehicles. Very easy to move and connect. The P3 is no different.

On GM's the wiring for the brake controller is above the kick panel under the steering wheel. Sometimes they have a connector that only requires a pigtail. If that isn't there they will have the wires bundled with black tape at the end. You'll be able to remove the pig tail for your F-150 and simply wire into the Sierra. If there is a connector under there, call Tekonsha and ask what pig tail you need. Their tech support is really good.

MFL wrote:
If it has the 7-pin connector under the bumper, it likely will have an oem supplied connector/adapter in the glove box. With Ford these oem connectors need to be hard wired to the controller, but very easy to do, especially for an EE. :)

Jerry

You just need the standard vehicle side pigtail that came with the P3, the GMC will just have wires without a connector.

A 2012 GMC will have a bundle of wires taped to a brace above the brake pedal. This is from memory. The GM blue goes to blue on the P3 pigtail. The GM blue with white goes to red on the p3 pigtail. The GM red with black goes to the P3 black, and the GM white to the P3 white. There may be an orange wire, don't worry about it.

Now go to the underhood power center and find the red wire that is bundled and stuffed between the power center and inner fender towards the rear of the plastic housing. Connect this to the inner stud located on the front of the power center. You need an 8mm fine threaded nut. You may have to install the fuse to power the stud, 30 amp IIRC, this powers up the controller.

But like MFL said the truck has to have the factory 7 pin out back. If it doesn't chances are it is also not pre-wired for the controller.

etrailer.com should have whatever you need. Adapter, entire harness they have it all. Plug and play.

https://www.etrailer.com/t1-2012_GMC_Sierra.htm

Call them if you are unsure about anything.

Got home last night. Phoned Tekonsha this morning. There is no plug-in adapter harness for a 2012 GMC, but GM provided the wires under the dash to hardwire in a brake controller. Apparently there's also a couple of wires under the front hood that have to be connected to as well. Tekonsha is emailing a tech. bulletin showing exactly how to do this so I'm all set.

Fortunately, I kept the original box for the P3 which has the universal hardwire adapter I'll need.

MFL wrote:
If it has the 7-pin connector under the bumper, it likely will have an oem supplied connector/adapter in the glove box.

It's a 7 year old truck - if there was such pigtail on the glove box, someone probably removed it years ago.

deltabravo wrote:

MFL wrote:
If it has the 7-pin connector under the bumper, it likely will have an oem supplied connector/adapter in the glove box.

It's a 7 year old truck - if there was such pigtail on the glove box, someone probably removed it years ago.

Maybe/maybe not, but in any case, it would be available from GM. In my experience, the OEM adapters work better than some plug/play after market. YMMV

Jerry

It is very likely that the truck has an integrated controller if it is a 2500HD, and they are very good. (I also have a '12 2500HD, previously used a P3). Unless there's something wrong with it it will be better than the P3.

Turned out there was 5 wires hidden way up under the dash. So hidden that I ended up going to a hitch shop. Hooked up the pigtail that I had kept in the original Prodigy box from years ago.

Also had to connect a power wire in the engine compartment next to the fuse box. It too was hard to find with the dust in there and hard to see.

So now the brake controller works great.