Every single light works on my trailer, left blinker, right, brakes, hazzards etc....but the running lights will not come on. We plugged it into a friends truck & it works fine....

So, now I understand I have a fuse issue somewhere but I'll be danged if I haven't checked just about every single one. Any help would be greatly appreciated.

03' F350 6.0 Diesel - truck does have another plug(s) in addition to the stock and a trailer brake box in the cab..

Any ideas?

The circuit for the running lights is a seperate circuit than the brakes,hazzards, and blinkers. If the running lights work on the tow vehicle it is not a fuse problem. If this is the case, check for power at the trailer plug receptacle on the tow vehicle. You will need to know which pin to check for power. Better yet, just turn on your parking lights and check for power on all pins. You should have power on one of them. If not, you have a wiring problem. I would suspect the receptacle. Check power in the wiring going into the recptacle to confirm.

It could be a fuse problem.

On many F series there is a separate, small, (about 1" X 3") fuse block. Look under the hood on the left back by the firewall. These are the fuses for the trailer circuits. Check to see if the running light fuse is blown.

Tom, the fuse you're looking for is just in front of your master cylinder. They are in a black plastic box with a hinged lid. All of the trailer fuses are Mini Blade type fuses. It will probably a 10 amp fuse, probably red. You will be shocked when you realize how many fuses your truck actually has. My F250 had at least 40. But it is good to have separate fuses for the trailer circuits. Once you know where they are, it will be no problem.

Artie

Well...I did find the fuse box but none were blown & still stuck...I actually have 2 receptacles and both won't run the running lights.

I have an electrician for another job coming over tomorrow & have him check..

If anyone has any other ideas, let me know.

How did you check the fuses? Sometimes you can't tell by looking at a fuse if it is bad. I usually use a volt meter and sheck with the power on.

Artie

If they are blade fuses, you can't tell by looking unless you pull them out and look at them from the side. You mentioned they were still stuck, did you pull them out. Bass Art is correct, sometimes a fuse will blow at one end instead of the middle of the element. The fuse will look good just looking at it, but in fact it is open at one end where you can't see it. You can make sure by pulling the fuse out and connecting an ohm meter across the fuse. It should have continuity with 0 ohms.

I meant I was still stuck...I replaced the fuses and still nothing. And my electrician buddy had to postpone. Guess I'll be running hazzards up to Lewisville tomorrow morning

tom

i had the same problem with my pickup. if you have the towing package the parking lights run through a seperate module in the fuse block. dont know exactly what it is called but the power runs though the fuse then the module. the ford mechanic said it was pretty high to replace the module so i dropped a wire from the license plate light down to the wiring horness.

ps 2002 ford 250.

Tom,
Go buy a circuit tester at either Wal-Mart or BPS. It is a simple plug-in type tester. It should cost no more than 3 bucks This will check to see if your plug is working or not and work back from there. This will help you zero in on your problem to determine if it is your wiring or plug. Good luck.

Which plug are you using? I had to use the four flat plug rather than the 7 pin round on my 05 F250. This was for my regualr trailer. All the lights worked fine until I turned on the running lights to my truck. Rewired the trailer for a four flat prong and plugged it in and presto. Go figure.

I didn't change anything on the trailer other than the plug.

The circuit tester is a great way to quickly check to see if you have juice to all wires going into the plug. I have also dropped a wire from the license plate light like mentioned earlier to give me trailer lights.

Good luck