Running lights don't work on the 5th when plugged into the F350. Plugged into the F250 work fine.

Chased the wiring and getting 13.8V at the 7 pin plug(F350) but 14.3V on F250

Discovered that the running light power is being drawn from truck tail light supply because of this:




Fuse 4 which should supply has been burnt out at some point by previous owner



Not pretty huh?

Does anyone know if you can get a new fuse box? My other option would be to run the proper wires to a separate fuse holder I think.

I believe but don't know for sure, that the fix they made may not have enough amps to work the running lights....

 

I'm a ways out from being able to yank that box out of my parts truck but I can tell you that yours has some higher amp fuses in it there than my box does. You have 25's where I have 10 and a 7.5. It's easier to show you than to 'splain where they are.

 

I have to confess to not having checked the other fuses, but I should as I'm pretty sure that's how the previous owner melted the box. Especially as you've noticed some that are already over amperage.

Thanks fella!!

 

That would work fine. Just flip the Under Hood Power Distribution Box and remove the Wires, put a Weather Proof Fuse Holder In-Line.

Now, that thing got HOT! I would look at the other wires AND do a Voltage Drop or AMP Draw on that Circuit. IF you have several needing replacement, you can obtain a 4, 6, or 12 Auxiliary Fuse Block and extend those wires to a mounting spot of your choice.

 

Just to close this out. I got round to doing it today after crappy weather and laziness.

Everything came apart easily. The supply for the fuse is via a metal plate as shown below, not a wire as I was expecting like the outer fuses on the box.




So I spliced the wire I could get to and then fed it through the front of the fuse box like this




Now I'll admit its possible that the plate not sitting flat to the fuse box, because that's where I attached the wire, it could give me challenges later but I hope not.

This is the final situation

 

Do yourself a favor and get an eye lug with the right size hole and put it between the nut and the eye lug for the feeder wire, that way the lug is sitting flat against the plate for the fuse box.

Good job on the work-around. That fuse holder got HOT! Bad/loose connection no doubt and maybe an oversized fuse at some point.

Good luck!