Okay folks, I need some help. I have a 2003 Expedition. I have the HD towing package and I have installed my brake controller under dash using the quick connector that came with the controller. The controller is getting power but I have no power (to the electric brake wire) at the 7-pin connector in the back of the truck. All the other lights (brake lights, running lights, turn signals) work and the trailer brakes work when connected to a different vehicle).
I assumed a fuse but have looked at the obvious ones (number 6 and 29 as identified as being related to the brake controller in the owners manual). I have also read the other posts to check for fuse 10 and relay 05 and 201 and 301. I can find fuse 10 and relay 05 and 201 but where is relay 301? I don't see it on the diagram for the fuse box on passenger side under dash. Any other reason there would be no power to the electric brake wire at the 7-pin connector?

 

I believe fuse #6 is for the trailer ligting and fuse #29 is for the trailer brake controler.
Have you checked fuse #35 and #43? They provide power to the 4-pin and 7-pin connector at the rear of the truck.

 

Have you tested it towing a trailer. Some controllers do not send power if you are not hooked to a trailer and brakes are needed.

 

I have tested it by raising the wheels on the trailer and having someone apply the brake in the truck. Nothing!! Wheels on trailer spin as freely as if no brake applied at all. I have tested all the other wiring in the 7-pin and it all seems to work fine except the one that feeds the electric brake. Oddly enough the brake controller even seems to detect when the trailer wiring harness is plugged in or not. When it is not plugged in I get an E-1 reading on the controller (which manual says is what to expect when trailer lighting not hooked up). When trailer lights are hooked up I get normal reading of output (in increments of 5% - just as controller documentation indicates I should) but still no power to the brakes.

I purchased a Haynes Repair Manual and was looking to check all of the fuses relays referenced above in this thread - I have checked all of them with exception of Relay 301 which is not in the passenger side fuse box. They Haynes manual indicates there are three other fuse boxes under the hood but I can only find one small one which is located right below the air cleaner assembly.

Where are (if there are any) other fuse boxes on this vehicle? 2003 Expedition