I'm a newbe here, nice site, lots of knowledge out there.

I do not have the search capability, been searching through 100's of posts looking for a solution to my problem. Hopefully someone knows a thread on my problem and can send me there or give me some insight on my problem.

I recently bought a 2000 f350 4x4 crew cab lariet, With 77k miles on it. it has the 7.3 with automatic. All wiring looks factory, clean, still has ford stickers.

I bought the truck to pull a car trailer. In order to connect the wiring from truck to trailer I had to buy an adaptor that connects the factory 6 blade to my trailer 6 pin harness. All lights and blinkers work. No problem. But my trailer electric brakes do not engage.

I have a 77 crew cab that I have been using as a tow rig for my trailer. All lights work fine as do the electric brakes. When my 77 is hooked up, the light on my brake controller in cab lights up. I can adjust this with an adjustment ****. Brighter the lights when engaged, harder the brakes come on. So I know the trailer brakes are fine.

Hook it to the 2000, no brakes. So I get my 12 volt test light out and have my brother hit the brakes while I check the connection on plug. I have two hot blades on the factory installed 6 blade. (Brakes are the only power on at this time, no running lights or blinkers are on.) When I plug in my adaptor I have two hot pins and my trailer brake pin (center pin)is very dim, When I place my tester on the center pin the light on the brake controller in dash lights up. When I take my tester off the center pin, light on controller goes off.

I have not checked my 77 to see which pin controls the trailer brakes. I am assuming it is the center pin. (on my 6 pin connector) Is this correct?
What would make the light on brake controller in cab light up when I place the test lamp on center pin?
Why would I have little power to the center pin, regardless if brakes are on or off or if my brother hand slides controller or turned adjuster ****. Power did not increase or decrease on test lamp. just dim?

Now that I'm thinking about it, There is a box on my trailer, maybe 6" x 6" x 3", I have always assumed it was a junction box for wiring. It's a 2002 trailer, would it need its own battery to make all work? And if that battery was dead would I get brakes from my truck wiring? I was reading from one of the threads that the new regulations with the break aways have their own battery. I have a break away.

Maybe that center pin is low amperage to keep that battery charged. And has nothing to do with the brakes.

I thought maybe my ground was weak, so I took some jumper cables and grounded my truck frame to trailer frame to make sure all was one unit. No help.

And finally, this psd has so many electric items and computers keeping all running, Can I really screw up something if I run another trailer brake controller back?

(Anyone know of a good book on "psd wiring for dummies"? I think I may need one.)

I will hook up the 77 tomorrow and see if all is fine with it. Then test lamp its wiring to see what runs what.

Thanks, Camano

 

After checking out the 77 truck wiring, simple fix. Just had to tear adaptor apart and switch two wires. The one for charging batteries and trailer brakes could go either way. It was a Hoppy adaptor. I called them before switching, they verified I would not screw things up. All is fine on Camano now. Trailer brakes and all wiring work fine. Took all for a drive, (empty trailer), that 7.3 does not even grunt. Of course no load yet. But the old 460 would of known there was a trailer behind.

Camano

 

Yeah, those adapters can sometimes have you scratching your head - glad to hear you got 'er fixed! You might have saved someone else a lot of heartburn with your discovery.

Steve