No Power

Back at it this morning checking all the fuse's I could find with the light up tester. All had power on both sides of the fuse.
I found the box with 4 relays under the hood on the drivers side but not sure how to check if they are working?
Should I mark the original position they are in, and move them around to check if I have power to the rear bumper plug in or??
Thanks, Mike

find a trailer shop in your area, they know what to look for, beats spending hours an even days to figure it out.

rlw999 wrote:


It took me just a couple minutes to check all of the fuses in the inside fuse box on my E450 (there are only two fuse boxes in my chassis - one in the engine bay and one in the passenger compartment) when I was trying to find the fuse used for the backup camera display that the previous owner hardwired in).

It takes like a second to touch each side with the probe so even though there are 43 fuses in that box, it doesn't take long to check them all. Less time than it would take me to look up the fuse chart online.

Maybe you misunderstand the tool I was describing, it's not a meter with 2 leads, it's a screwdriver like probe -- clip the ground wire to something metal, then just stick the sharp probe end into the hole on top of the fuse (even mini-ATC fuses have that hole) and see if the light comes on. No need to stare at the meter display and wait for it to register voltage for each one, the light either comes on or it doesn't so you get instance confirmation and can go on to the next one.

In my case it turned out to not be a fuse at all but a bad splice to the radio harness where he tapped off the power.

Not sure what yr you have but OPs 2006 has MORE than two fuse boxes..

If it follows close to the 2006 F250 I had, there was TWO under the dash on the drivers side, there were THREE under the hood. One of the three under the hood was for the TOWING wiring fuse and relay box and on a F250 that was on the drivers side under the hood.

The 2003 F250 I had had FOUR fuse boxes, two under the drivers side dash two under the hood, one under the hood was the TOWING wiring fuse and relay box.

Had a 97 F250 with basically the same setup..

Have 2013, 2019, 2020 all with fuses under the hood for the towing wiring..

If you notice, a common theme is ALL of the fuses associated with the TOWING wiring was not under the dash but it was under the hood and it was completely SEPARATE from all other functions.

It is not easy to find, it is a little narrow black plastic box that is often pretty well hidden and the cover is pretty stubborn to remove.

Telling someone to look under the dash for the towing fuses is most likely not going to be of any help if Ford used this same wiring setup on E450 (which from the info and links I posted seemed to indicate I am correct)..

Thanks for all the info so far.
I'm the worst at electrical problems.
I will get back at tomorrow afternoon, and will get back with what I find.
Mike

Mike P. wrote:

I know it was meant to be helpful, but..

There is at least 100 fuses spread out over 4-5 different fuse/relay boxes which may be under the drivers side dash, under the passenger side of dash and both sides of the engine bay..

Add in the fact that the OP is dealing with a "E450 Van chassis" RV fuse boxes often get moved or rearranged by the RV manufacturer..

Finding and testing every single one of those fuses without a game plan will result in a lot of frustration..

Especially considering there ARE "charts" that give locations and function of fuses..

Additionally, most fuses use in modern automobile applications are the even smaller ATM (MINI) plastic fuses which will make even more challenging to nail with meter leads..

ATC vs ATM FUSES

It took me just a couple minutes to check all of the fuses in the inside fuse box on my E450 (there are only two fuse boxes in my chassis - one in the engine bay and one in the passenger compartment) when I was trying to find the fuse used for the backup camera display that the previous owner hardwired in).

It takes like a second to touch each side with the probe so even though there are 43 fuses in that box, it doesn't take long to check them all. Less time than it would take me to look up the fuse chart online.

Maybe you misunderstand the tool I was describing, it's not a meter with 2 leads, it's a screwdriver like probe -- clip the ground wire to something metal, then just stick the sharp probe end into the hole on top of the fuse (even mini-ATC fuses have that hole) and see if the light comes on. No need to stare at the meter display and wait for it to register voltage for each one, the light either comes on or it doesn't so you get instance confirmation and can go on to the next one.

In my case it turned out to not be a fuse at all but a bad splice to the radio harness where he tapped off the power.

rlw999 wrote:

Mike P. wrote:

According to the Ford book that came with the unit new, I'm not sure what fuse it is that I should look for?
Mike

If you're not sure which fuse to check, you could just check them all. It's pretty fast and easy with a 12V test light (looks kind of like a screwdriver with a pointy tip, a light in the handle, and a ground wire with a clamp). The fuses have a pair of holes on top where the contacts are exposed, just poke the test light into each side of the fuse, if it has power on one side but not the other, you know it's blown.

I know it was meant to be helpful, but..

There is at least 100 fuses spread out over 4-5 different fuse/relay boxes which may be under the drivers side dash, under the passenger side of dash and both sides of the engine bay..

Add in the fact that the OP is dealing with a "E450 Van chassis" RV fuse boxes often get moved or rearranged by the RV manufacturer..

Finding and testing every single one of those fuses without a game plan will result in a lot of frustration..

Especially considering there ARE "charts" that give locations and function of fuses..

Additionally, most fuses use in modern automobile applications are the even smaller ATM (MINI) plastic fuses which will make even more challenging to nail with meter leads..

ATC vs ATM FUSES

Since OP doesn't have ANY stop/turn/tail/break, charge power they might wish to look at the wiring right at the socket on the RV and trace back to the wiring harness.. I find it interesting that ALL have "failed" so there is a chance that the socket is not even connected to the wiring harness or if it is connected it was a botched job and the wires corroded off..

There is no one "master fuse" for all towing connections that I am aware of, there should be separate fuses and relays for stop/turn/tail/brake..

There is on many rigs a fuse block under the hood that has separate fuses for each of the trailer connector. If you don't have one, get a 12 volt DC test light.
The fuse block should be in the chassis owner's manual.

Mike,

Mine came with a 60 amp blade fuse. They are hard to come by. In my 2005 it is in a rectangular box in the engine compartment about 2 feet back from the grill on the drivers side.

I put in a 50, and it blew. I put in another 50 and it blew. I replaced it with an automatic circuit breaker, and all is well.

There is also a circuit breaker for the tail lights in the same box. (and yes, I managed to blow that, too.

Mike P. wrote:

According to the Ford book that came with the unit new, I'm not sure what fuse it is that I should look for?
Mike

If you're not sure which fuse to check, you could just check them all. It's pretty fast and easy with a 12V test light (looks kind of like a screwdriver with a pointy tip, a light in the handle, and a ground wire with a clamp). The fuses have a pair of holes on top where the contacts are exposed, just poke the test light into each side of the fuse, if it has power on one side but not the other, you know it's blown.

Check the ground for the trailer connector before getting too involved in looking for light circuit problems. Then check the ground a second time.