anyone know what the trailer tow relay is used for on my truck? its mounted on the drivers side under the hood.it looks like it has a brown wire on it that goes to the back of the truck. thanks steve

1990 f350 4x4 crew

 

Do you mean an inline fuse? Sounds like it goes to the trailer brakes...why would you want to mess with it?

 

i was hooking up my trailer lights.got a book today i found out that is activated by the headlights, it keeps the trailer running lights seperate from truck lights.

 

That sounds cool...

 

Can you tell me what relay number it is you show for the trailer towing? I do not have an owner's manual and I am trying to track it down. Thanks for the help.

 

bukwild my book(haynes) doesnt show it by by number. it just says trailer/marker light relay on wiring schematic.(brown and white wire goes to rear of truck)its located under the hood, driverside. it just says "trailer tow" its next to two others,"fuel pump" and "EEC power" they got a black plastic cover on them. my truck is a 1990 f350.it sounds like you need a book too. steve

 

I finally tracked down my problem. There was a seperate fuse panel up against the firewall that holds six mini blade fuses. It is just for the trailer lights. As soon as I opened it up, I noticed a 20amp fuse blown. I replaced it and now have all lights again. I appreciate all the input. Hope I can help someone else out sometime.