Seneca trailer brake control

[Capt. Rich]

Hello All, I have a 2008 Seneca 35GS. The hitch has a 7 prong connector. There appears to be a wiring harness under the dash on the drivers side but no controller. I would have thought a rig of this size would come with a factory controller. Should I check with GM and see what they offer as OEM or just buy a good aftermarket like Tekonsha or DrawTite? Thanks

[Sundancer330]

I would look into a Tekonsha P3 and also buy the harness so its just plug n play, its a great controller and customer service has come through when I had sticky buttons with an overnight replacement.

[WinnieView]

We don't have one in our Seneca, a Tekonsha, but did install one in a previous motorhome.
All the guys at Diesel Place agree that you need this information;

https://www.gmupfitter.com/publicat/bull/bull66.pdf

And maybe this too;

5500 Trailer Brake Blue Wire- I cant find it! - Diesel Place : Chevrolet and GMC Diesel Truck Forums

Let us know how it works out for you.