I may be picking up a enclosed triailer sometime this season so I picked up a couple of controllers and got one all wired up in the peekup easy as pie...

Now for the moho... dove under the dash and could only find a big white wire loose that may go back there for the brake application.
Is there some sort of set up like the trucks where you plug something in? There is a round capped off cannon plugs there by the obd2 connector... could that be it? Or was I looking in the wrong place and need to look under the hood?
Or will I have to do it the old fashoned way and pull power from the fuse box, find a ground and a brake switch wire to tap and make sure that big white wire is what I think it is?
I will also probably have to do something out back to hook up charging power I remember a bundle of wires out back that may need attention.

Thanks in advance if you take dive under the dash to look! I know that is not easy I almost thought I was trapped under there for a while!

I could'nt believe where they put the stupid fuse panel for my MoHo. You need to be 75lbs and as flexible as soggy spagetti to get to it....

What chassis do you have?

I've got a W22 and it was "pre wired".....meaning the brake control wire (12ga blue wire) was routed to the back of the machine. I'm pretty sure its a 12guage wire, and mine had printing on the insulation that said "brake". It's shoved up under the dash and hard to find, but it's there! The power/ground/brake switch wire had to be spliced into. On mine there was an open circuit on the fuseblock mounted by the drivers left foot area, and the brake switch was easy to tap into. There's a switch on the steering column mount that activates the brake lights. It has 3 wires, the blue wire is the one you're looking for. Splice into it for the brake function of the controller. The ground can go to just about anything under the dash as long as it's a structural member and not just a dash support.

Have fun crawling around under there!!!

Thanks for the replies... I did some searching over on the workhorse forum on irv and there were some saying the pre-wires are on the other side from where I was looking... like more above the gas pedal. Great there is even less room over there, but at least I dont have to cram myself into a corner so deep!

I just looked at your signature 2006 fleetwood 32...do you have a Southwind 32V?
If so, that's what I've got so the wiring should be the same. The brake control wire was above the steering column near the brake pedal switch. I couldn't see it from crawling under the dash by the gas pedal, but when I went under the side by the brake pedal I could see it.

It is a w-22 chassis I think but I have the lower down the food chain terra model.
Will dive down there again in a day or two. Will make sure that my wife is around this time in case I need help getting out or to play go fetch.

The wiring should still be the same as the Southwind though.
I hear you about getting stuck. There were a couple times I got that panic feel of "oh crap, I contorted myself to get in here but my body won't contort the opposite way to get out!!"

I feel your pain... it was sooooooooooooooooo worth the few extra $$$ it cost me to have the stealership put mine in when I bought it.

FWIW I believe all newer Workhorse chassis are partially prewired. Mine was, per the guy who installed the module. As long as the 12-ga brake line is run, the rest is basically cake (except for the Cirque du Soliel contortions).