Community Forums

bumbie · 04-14-2022, 07:13 PM

While on a recent trip we noticed the coach did not have any tail/stop/turn signal lights. The toad's were working. Checked the under the dash fuses and they looked okay. Couldn't find or get into the under the hood fuse box.

Headed toward the next city to see if we could get into a Ford dealership for repair. While parking noticed coach lights were working again. Skipped the Ford dealership (they were closed) and continued on with lights working (500+ mi). Made the turn toward home (400 mi to go) and noticed back end wasn't working again.

My plan is to find/get into the fuse box under the hood before going to the dealership.

Other than a bad fuse/ground...what else could cause the loss of all rear lights?

Anyone experience a similar issue?

BTW...it is under warranty. The dealer made it clear that if they decide it is a Newmar issue and not a Ford issue we would foot the bill for the diagnostic...which is why I'm going to check the fuses first.

tomato · 04-15-2022, 10:47 AM

Quote:

Originally Posted by bumbie

While on a recent trip we noticed the coach did not have any tail/stop/turn signal lights. The toad's were working. Checked the under the dash fuses and they looked okay. Couldn't find or get into the under the hood fuse box.

Headed toward the next city to see if we could get into a Ford dealership for repair. While parking noticed coach lights were working again. Skipped the Ford dealership (they were closed) and continued on with lights working (500+ mi). Made the turn toward home (400 mi to go) and noticed back end wasn't working again.

My plan is to find/get into the fuse box under the hood before going to the dealership.

Other than a bad fuse/ground...what else could cause the loss of all rear lights?

Anyone experience a similar issue?

BTW...it is under warranty. The dealer made it clear that if they decide it is a Newmar issue and not a Ford issue we would foot the bill for the diagnostic...which is why I'm going to check the fuses first.

Sounds a lot like the PDM issue Freightliner has been dealing with for years on the diesel chassis. They say internal solder joints are failing, but the rear light issue is intermittent. I would check the wires going in and out of your fuse box where the rear lights feed. Also, make sure the blade fuses are nice and tight.

Rev. Roy · 04-15-2022, 12:26 PM

Uh Tomato, it's a Bay Star so it is a Ford chassis. PDM was my first thought also but realized it was a gasser. It sure sounds like a ground issue to me. The fact that they quit, then worked, then quit again point that way. I would start checking at all the connections then for a ground that may be loose or corroded. If it is a broken ground wire it will be hard to trace. I know that may not be something you want to deal with but bad ground is the most common reason for rear light problems on gas motorhomes.

tomato · 04-15-2022, 01:06 PM

Quote:

Originally Posted by Rev. Roy

Uh Tomato, it's a Bay Star so it is a Ford chassis. PDM was my first thought also but realized it was a gasser. It sure sounds like a ground issue to me. The fact that they quit, then worked, then quit again point that way. I would start checking at all the connections then for a ground that may be loose or corroded. If it is a broken ground wire it will be hard to trace. I know that may not be something you want to deal with but bad ground is the most common reason for rear light problems on gas motorhomes.

I realize that. That is why I said it was "a lot like..." Good point on a potential ground issue.

bumbie · 04-18-2022, 12:58 PM

Thanks for the suggestions. Away from the coach for a week or so.......the fun will begin when I get back....lol.

Does anyone know if the ground can be attached to frame anywhere along the line or is it an industry standard to have it in a particular place? Spoke to Ford advisor....he said what is dropped off at Newmar as a 'stripped F53 chassis' does not always come out with the same fuse assignments.

mgtibb · 04-18-2022, 04:26 PM

Check to see if there is any water/corrosion in any of the tail lights. I had water in one of mine that was causing weird issues with lights and cruise control disengaging.

Steve-W · 04-18-2022, 04:45 PM

There is most likely a Ford provided connector on the rear frame rail where Newmar connects the wiring that goes the last few feet to the rear cap lights. That would be my starting point to troubleshoot, could be a improperly seated connector or similar.

jaydee325 · 04-19-2022, 06:05 AM

Quote:

Originally Posted by Steve-W

There is most likely a Ford provided connector on the rear frame rail where Newmar connects the wiring that goes the last few feet to the rear cap lights. That would be my starting point to troubleshoot, could be a improperly seated connector or similar.

I agree with this.

On an earlier model F53 chassis motorhome I had, the brake light fuse blew due to a short in the tow dolly wiring. That prevented the cruise control from working as well as not allowing the transmission selector to come out of park (all of these features rely on the brake light circuit as a trigger).

bumbie · 05-11-2022, 11:23 PM

Took our BS to the Ford dealer. While doing the light check before pulling out...the lights were working!! They had it for 2 weeks and were unable to duplicate the problem. No trouble codes generated. Did read a post on FB for same year and model with the exact same problem. The owner said Ford couldn't find the problem with their coach. They took it to a RV service center who discovered a faulty multi directional switch and a stressed flasher relay. Since Ford couldn't duplicate the problem they won't replace anything.

We have an appt at a Newmar service center in 2 weeks for a few other "minor" problems. Maybe they help find the problem.