Brake Controller Does Not Work when Using 7-Pole Round to 7-Pole Blade Adapter

Question:

After installing this part all the lights work on my trailer including the brake lights but the brakes themselves do not work. The brake controller in the truck does not come on. The brakes on this trailer work with two other trucks not using the adapter and the brake controller in the truck works when not using the adapter. Is it possible that the wires need to be switched around in the adapter to get the brakes to work?

asked by: Rob P

Helpful Expert Reply:

It does sound like something is mismatched in the wiring. Either the truck or the trailer would appear to not be following the standard pin out. On the output side of adapter # HM47425 the brake pin is in the 5 oclock position if looking at the pins. If looking at the back of it where the wires attach it would be in the 7 oclock position.

I have included a link to a help article that shows how different trailer connectors are normally pinned out so you can compare them with what you have and then adjust accordingly.

expert reply by: Michael H