Fuse blows when I back up (06 E-350)

2006 ford E-350 Every time I shift the van into reverse the trailer backup/running lights fuse blows.

It does this when the trailer is hooked up and when it is unhooked so it is not the trailer.

The van backup lights work fine.

Fuse is fuse 24 under the hood (Trailer tow running lamps and back-up lamp relays) Are there any known issues or where should I start troubleshooting on this? (I dislike wiring issues)

I don;t know of any known issues.. but I would start with the switch that controls your reverse lights and work your way back.

I had the same problem on my way to the $2011 Challenge in my '06 E-150. I pulled the "Trailer Backup Lamps Relay" out of the PDC under the hood and all my problems were solved.

I've had the relay sitting here on my desk at work ever since I got back from the Challenge that year and one of these days, I swear I'm going to test it to see if the relay is bad. Some day. I gave the wiring a quick look and didn't see anything that looked like it would be shorting out, and it happened with or without the trailer hooked up, so I know the problem is on board the van somewhere. Since everything works without that relay and my trailer doesn't have any reverse lights or a surge brake that needs to be defeated, I haven't been all that motivated to find out exactly what's going on.

check the trailer wiring.

Don't back up.

iceracer wrote: check the trailer wiring.

he said it did the same thing whether the trailer was hooked up on not

wvumtnbkr wrote: Don't back up.

+1

Stop me if you've heard this one:

A man goes to the doctor. "Doc, it hurts whenever I do this!" Doc says "Don't do that!"

‘Doctor, doctor, I think I’m suffering from déjà vu!’ ‘Hang on! Didn’t I see you yesterday?’

‘Doctor, doctor, I think I’m a dog.’ ‘How long have you felt like this?’ ‘Ever since I was a puppy!’

‘Doctor, doctor, I think I’m a bridge.’ ‘What’s come over you?’ ‘Two cars, a truck, and a coach.’

‘Doctor, doctor, I think I need glasses.’ ‘You certainly do. This is a garage.’

‘Doctor, doctor, I keep thinking I’m invisible.’ ‘Who the hell said that?’

wae wrote: I had the same problem on my way to the $2011 Challenge in my '06 E-150. I pulled the "Trailer Backup Lamps Relay" out of the PDC under the hood and all my problems were solved.

Thanks. Just tried that and that will at least stop me from blowing fuses until I figure it out since I have electric brakes and I can live without backup lights on the trailer if it even has them.

I swapped the Trailer backup relay with the running light relay right beside it (same part number) and the fuse still blew so looks like it is not the relay.

I have been trying the don't back up method and it works about as well as the rhythm method.

So I guess it is isolated to van wiring past the relay

Well, I guess you saved me from having to get around to testing this relay :)

Honestly, the only thing that I've ever personally seen the backup light power connection do for a trailer is to defeat the surge brakes so that you can reverse a trailer equipped with them. If you're motivated enough to try to actually fix the problem, I'd probably start in the connector under the bumper. I hear those are prone to being invaded by water and getting corroded and shorted out.

wbjones wrote:

iceracer wrote: check the trailer wiring.

he said it did the same thing whether the trailer was hooked up on not

Yeah I got confused with trailers and backup lights.