I recently purchased a used 2005 E-150 that I am installing a trailer hitch and wiring on. In a few weeks I will be making a 1800 mile trip pulling a trailer with a total loaded weight of about 2000 lbs. I have read some of the archived threads on trailer wiring and towing. I looked under the van and I have the 4 wire plug on the driver side next to the spare tire. I checked the fuse panel and relay locations to see if the proper fuses and relays are in place, and the only one that is missing seems to be the number 4 relay (listed as "trailer tow left turn") in the engine compartment relay module. The owner's manual cautions that these relays should be serviced by the dealer. Is this true or can I disconnect the battery and plug it in myself?

I was going to install a transmission cooler but discovered that the van already has the transmission and power steering cooler installed in front of the radiator. That surprised me in that I don't think that the van has the tow package, for example the 3 wire plug for the brake near the rear bumper is not there. There is the protective hose for the wires, but there are no wires in it.

Any info on that missing relay would be appreciated.

And Happy New Year!

 

I installed new lights on my trailer.When i went to go test them the break lights came on when i used the turn signal.I didnt want to go and rewire the plug again,becuse i had taped it all up.All i had to do is rewire it down at the lights at the end of the trailer.Every thing worked after that.If you want to be on the safe side you can fuse it down at the female trailer plug at end of the truck.

 

You can replace the relay yourself. The local parts stores should carry it.