Tail lights, brake lights and turn signal --don't work

[Clydelittle]

My tail lights, brake light and turn signal on the rear of my DX3 are not working...no lights at rear. The front works and the lights on my trailer work.
Dynamax said take it to Freightliner...there is no fuse...anybody else have that happen or know anything?????????????

[dbledan]

Originally Posted by Clydelittle

My tail lights, brake light and turn signal on the rear of my DX3 are not working...no lights at rear. The front works and the lights on my trailer work.
Dynamax said take it to Freightliner...there is no fuse...anybody else have that happen or know anything?????????????

I cannot see which year you have or which chassis your DX3 has. I found several fuse box diagrams. I am betting yours is either under the hood (most likely) or in passenger compartment passenger side possibly. There will be a fuse for them.

Are the running lights out as well or just brake and turn?

I had issues once where water was in the lenses for the turn signal and would short it out with the blinker or brake light. I would look for water and drain it then swap the fuse.

If not the fuse or water then you may want to start checking wiring harnesses.

Post the chassis and year you have and we can look it up. I am on the app and cannot view a signature.

[redskins2856]

Originally Posted by dbledan

I cannot see which year you have or which chassis your DX3 has. I found several fuse box diagrams. I am betting yours is either under the hood (most likely) or in passenger compartment passenger side possibly. There will be a fuse for them.

Are the running lights out as well or just brake and turn?

I had issues once where water was in the lenses for the turn signal and would short it out with the blinker or brake light. I would look for water and drain it then swap the fuse.

If not the fuse or water then you may want to start checking wiring harnesses.

Post the chassis and year you have and we can look it up. I am on the app and cannot view a signature.

X2 on fuse boxes. I don't have a Dynamax but my 2016 freightliner tractor trailer has 4 fuse boxes. Two under the hood,the one on the firewall on mine houses the fuses for marker and brake lights.

[TheWolfPaq82]

Talking fuses ?? are the front lights and the rear lights on separate circuits, on two different fuses ?? Don't most vehicles have "One" fuse that controls running/marker/taillights and another fuse for the brake lights ?? Sounds more like a harness problem leading to the rear of the vehicle.

[dieselguy]

Many newer vehicles have fuses for individual lights as opposed to older models with a single fuse for say parking lights. I have a 2005 Chevy Colorado that has separate fuses for RH and separate fuses for LH hand tail lights as well as separate fuses for RH and separate fuses for LH front parking lights just as an example.

[dbledan]

If the OP is on an M2 chassis then they have these to contend with.

The trailer fuse box and the taillight fuse box, on vehicles so equipped, are mounted on a bracket with the chassis module on the left-hand frame rail aft of the cab, or on a crossmember at the end of the frame rail. These may be referred to as the chassis fuse box or chassis PDM.*

[dieselguy]

dbledan … you posted it way better than what I was trying to point the guy to.

[dbledan]

There's another thread with a Georgetown with the same problem active now too. I guess freightliner may have a recall on those from where that thread was headed. Not sure if it would apply here as well or not. There does not seem to be the same control bus on this chassis.

[jimmoore13]

Since both circuits are out:
1) tail lights
2) brakes/signals
check your ground wire(s).

Almost all vehicles use the chassis as ground. A (typically white or green) wire will be "grounded" to the chassis with a screw. It is entirely possible that there is a single ground wire and that both fixtures are tied together, because the tail lights are just one signal, so a sing'e ground wire will do.

If you can find the wiring harness to the tail lights, it's likely to be a 3-wire bundle. One strand for tail lights and one strand each for left brake/signal and the other strand for the other brake/signal. Ground to that circuit would be at the fuse panel at the front of the vehicle and then thru the chassis (frame) to a wire screwed in somewhere as close as possible to the fixture where the 3-wire bundle enters the fixture it feeds.

It's not necessarily true that the fed fixture will jumper over to the other fixture, but it's very possible. If the "feed" bundle splits before the fixtures, it's possible there are two ground wires...one for each fixture. And that would undermine my hunch. But it's just as possible that one fixture is the master, and the other slaves to it with wiring up in the body somewhere.

At any rate, don't rule out a ground problem. Unlike a purpose-built auto or truck, RVs are patched together in very rudimentary ways, and what would not pass muster for the tail lights on your car is common practice on what are essentially home-made contraptions with off-the-shelf lighting fixtures tacked on almost as an afterthought. Anyone who has owned a trailer has experienced lighting issues related to bad ground.

Anyway, just food for thought.

[berkdriver]

Contact your Forest River Techs about the issue. I know some Berkshire's are experiencing the same issue there is a recall issued for them. I'm not sure if the recall came from FR or Freightliner for them as I have not received a notice on my Berkshire.

[MR.M]

Originally Posted by jimmoore13

Since both circuits are out:
1) tail lights
2) brakes/signals
check your ground wire(s).

Almost all vehicles use the chassis as ground. A (typically white or green) wire will be "grounded" to the chassis with a screw. It is entirely possible that there is a single ground wire and that both fixtures are tied together, because the tail lights are just one signal, so a sing'e ground wire will do.

If you can find the wiring harness to the tail lights, it's likely to be a 3-wire bundle. One strand for tail lights and one strand each for left brake/signal and the other strand for the other brake/signal. Ground to that circuit would be at the fuse panel at the front of the vehicle and then thru the chassis (frame) to a wire screwed in somewhere as close as possible to the fixture where the 3-wire bundle enters the fixture it feeds.

It's not necessarily true that the fed fixture will jumper over to the other fixture, but it's very possible. If the "feed" bundle splits before the fixtures, it's possible there are two ground wires...one for each fixture. And that would undermine my hunch. But it's just as possible that one fixture is the master, and the other slaves to it with wiring up in the body somewhere.

At any rate, don't rule out a ground problem. Unlike a purpose-built auto or truck, RVs are patched together in very rudimentary ways, and what would not pass muster for the tail lights on your car is common practice on what are essentially home-made contraptions with off-the-shelf lighting fixtures tacked on almost as an afterthought. Anyone who has owned a trailer has experienced lighting issues related to bad ground.

Anyway, just food for thought.

X2

[PenJoe]

Originally Posted by jimmoore13

Since both circuits are out:
1) tail lights
2) brakes/signals
check your ground wire(s).

Almost all vehicles use the chassis as ground. A (typically white or green) wire will be "grounded" to the chassis with a screw. It is entirely possible that there is a single ground wire and that both fixtures are tied together, because the tail lights are just one signal, so a sing'e ground wire will do.

If you can find the wiring harness to the tail lights, it's likely to be a 3-wire bundle. One strand for tail lights and one strand each for left brake/signal and the other strand for the other brake/signal. Ground to that circuit would be at the fuse panel at the front of the vehicle and then thru the chassis (frame) to a wire screwed in somewhere as close as possible to the fixture where the 3-wire bundle enters the fixture it feeds.

It's not necessarily true that the fed fixture will jumper over to the other fixture, but it's very possible. If the "feed" bundle splits before the fixtures, it's possible there are two ground wires...one for each fixture. And that would undermine my hunch. But it's just as possible that one fixture is the master, and the other slaves to it with wiring up in the body somewhere.

At any rate, don't rule out a ground problem. Unlike a purpose-built auto or truck, RVs are patched together in very rudimentary ways, and what would not pass muster for the tail lights on your car is common practice on what are essentially home-made contraptions with off-the-shelf lighting fixtures tacked on almost as an afterthought. Anyone who has owned a trailer has experienced lighting issues related to bad ground.

Anyway, just food for thought.

X2 Separate circuits with one thing in common-ground.

[Clydelittle]

First thanks to all of you for the replies.
My DX3 is a 2019 36 ft purchased July 2018.
I have solved the problem. The connector at the rear of the RV behind the bumper became disconnected. It actually did not have a latch it just pushed together and was easily pulled apart(not now after my two cable ties and lots of tape).

[dbledan]

Originally Posted by Clydelittle

First thanks to all of you for the replies.
My DX3 is a 2019 36 ft purchased July 2018.
I have solved the problem. The connector at the rear of the RV behind the bumper became disconnected. It actually did not have a latch it just pushed together and was easily pulled apart(not now after my two cable ties and lots of tape).

Thanks for checking back in to tell us.