I am trying to get my trailer working. Someone who had my truck before messed up the trailer harness. I think they blew the trailer fuse or relays. I have an 02 f350 and I need the location of the trailer lighting fuses and relays. The chiltons manual said relay box 4. I can't find it..
I have B+ and ground, no trailer brake or right turn signal or parking lights.
Trailer brake works fine at the controller, signal is lost somewhere.
have the same problem with the 02 7.3 I just picked up.Have trailer running lights but no turn or stop signals.A tester says no power for these circuits at the plug in.Dont see that fuse box under the hood..Thought it was only under the hood on the gassers??? Any comments welcome....Thanks...........
I had the same problem on my 01 F-250 Powerstroke. I had brakes and running lights but nothing else. It turned out to be fuses. Under the hood on the driver's side there is a fuse box. Remove the cover and there shoud be a row of big fuses and a couple rows of small ones. Check all of these fuses. I had one large one burnt out and one small. Ireplaced them and everything works great.
On my 02 PSD the fuses are right under the steering wheel. Loosen the 4 spring loaded screws and the cover pops off exposing the fuses. There is a fuse diagram in your owners manual. Remember there are fuses for BOTH your truck turn signals and your trailer turn signals! They use mini fuses. If you cant find the right fuse repost and I will look it up in my owners manual. Good luck
2002 F250 PSD 4+4 ex-cab 6 spd
2002 Ford Taurus--1994 Taurus
1965 Ford 3000 and 1947 8N tractors
Thanks for the info guys.The turn signal relay is under the hood on the left side fender,I could hear it clicking to find it,its working fine..My 2000 PSD had this behind the radio in the dash when I had to replace it.But the fuses are under the steering wheel just like you said.My owners manual says its a 20 amp fuse in position number 6 for the trailer tow turn/stop relay..Put new fuse in even though it didnt look burnt.Still all the lights on the truck work right ,but only have running lights on trailer,no turn or stop lamps.trailer is fine,I plugged it into my 02 150 and everything works right..still baffled..Tester says no current at the plug for those circuits.Wiring up to the plug looks good. I think I will ask the dealer after the holiday weekend..Thanks for your help guys..Is MUCH appreciated...
The trailer lights went out on my boat trailer for almost no reason, there were no shorts. I traced the problem to the connector on back of my 04 Ford F250 Diesel. The wires were dead, except for the running lights. After spending hours tracing and pulling apart harness connectors underneath the truck, I finally determined that the problem was up front. Even though the truck is under warrantee, I hate to visit the service department, it is one heck of a in-convenience, I came here instead. This is what I learned.
Late model Ford trucks have seperate fuses for the trailer connector, you know the one located near the hitch. (different than other vehicles that I owned) It seems that these mini fuses, even though they have a rating similar to the big ones, seem to blow for almost no reason. After reading above, my problem was quickly determined to be a 20 amp fuse. On the late model F250s, the fuse box is located inside the cab, to the left of the steering column, behind a large compartment cover secured with four plastic pop out screws. I replaced the 20 amp mini fuse and "wala", the trailer lights work.
Probably a good idea to keep plenty of mini fuses on hand, several sub-circuts are protected with mini fuses. Glad this web site was here, saved me from another trip to the service depart. I'll talk about the super sensative seat belt retractors, you know, the kind that lock up and trap you, perhaps this one is best left for another forum.
Last edited by algutkin; 05-31-2004 at 05:10 PM.
if fuses are blowing, there are problems, esp if it is a 20 amp fuse and you have only a few lights on a trailer (boat trailer vs eclosed trailer).
Find out why the fuse blew and fix the problem rather then patching it with a new fuse next time.
I'm not going to say that I know it all about trailer connectors and lights, however, I have been hooking up lights and wiring connectors for 50 years without blowing a fuse.
There are two four types of fuse protection common to vehicles, fusable links, circut breakers, fast fuses, slow burn fuses. Fusable links are the hardest to find, they look like normal wires and are difficult to find. Slow burn fuses arer the best, they take a short term licking before blowing. In any case, there is no way that a volt/ohm testor should burn out a fuse, yet it did. Same problem occurred with my 2001 Diesel Excursion.
Sure, in most cases, boat trailer lights are under water, get corroded, wires break off and short out. In other cases a trailer could drain more than 20 amps and blow a fuse. Consistant blowing of fuses would indicate a short, which should be traced and fixed. Not the case here, the fuse blew with use of a meter. Perhaps Ford uses inferior fuses.
The information contained here is not supposed to help people cure a short problem, but, merely be informative on how Ford protects the trailer circut, and where to find the burned fuse.
I would have to agree with f350xlt460, if the fuses are blowing there is a reason. I think tracing a short out would be far easier than trying to repair a burnt down rig. If you have a volt meter, start at the plug in the back. Ohm each wire to ground, ground should read Zero Ohms, the rest should read open. Then check between each wire. It a place to start, and you need to start somewhere. Also, drop the spare tire, there should be on the driver side frame rail a large interconnect for all the tail lights and Trailer wiring. Make sure you are getting good contacts there. You may want to check your trailer wires there for voltage. Good luck at any rate, going to take some time to figure it out.
There was more than one fuse to be used on my trailer light/electric brake set up. they were all the big ones. i think there was three. musta rewired my trailer 3 times before i even checked for fuses. you think if they had the connector it would be ready to use.
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