Guys,

Have read a lot of posts on this prior to posting......."al's" also....

I have a 2000 E-150 that HAS NO wiring in the back (have looked and guarantee no wring from front of van back).....4 or 7. I have a 4 pin harness attached to the brake lights that's worked fine for 10 yrs. I now want to run a 7 pin for buddy's car trailer, etc and am having a tough time. I also have the 4 to 7 conversion adapter/connector for back of van that will only need the white (ground) black (hot) and blue (brakes) wires connected to finish install.

I have the brake controller installed and plugged with the factory brown splice receiver (next to emg. brake) and orange brake light on controller works when I depress brake.

I have found the 4 pin factory splice under hood off main harness near master cylinder.....(grey capped 4 pin connector, w/drk. blue, orange, grey/red stripe, and yellow....can't attach) I get on a constant hot lead but nothing off the drk. blue when pressing down brake.

I checked the under hood relay box and the only thing not installed with the 1 large (5 pin/horn style) relay, but large fuses and smaller relay/s were there. I moved the horn relay into the empty position to check the drk. blue wire I mentioned when pressing the brake down......still no power to drk. blue. The key shouldn't need to be on to check these?....correct?

I'm stumped......maybe one of you can tell me what/where to try/or next, before I have to open up main harness under my foot area (outside under van) to tie into.

I'd appreciate any help possible? Thanks!

 

Bit the bullet and ran 2 direct 12g. wires from the engine compartment to back of van. Found a blue that was working with brake in main harness (before adapter mentioned in prior post), tapped into that and now running the hot.......

Question............this hot should be (fused)........does it need to be key activated or constant?

Thanks

 

The factory wiring in my 97 is fused @30amp ( 10 ga) and is only hot with key on.
You can "up grade" to a 20 amp breaker(12 ga), it will reset / protect, one for the brake controller also!
No real need to relay the battery hot wire. Is the car trailer enclosed? battery in it ?
If so a draining trailer battery will pull down starting battery,remember to just disconnect 7-way plug.

 

Thanks for the reply......did the in-line fused, key activated wiring.

All done....needed this trailer wiring to pick up a new 12,000 lb garage lift, and wish I already had it to do this job!

Thanks again.