Rear turn signals don't work

[jim4272]

1999 Fleetwood Discovery. Getting ready to leave on a trip and my rear turn signals don't work. I found a fuse box under the dash by the accelerator pedal and it has a turn signal fuse but it's not blown. I also have a fuse box just behind the rear wheels, but I don't see a turn signal fuse there. The front turn signals work but not the rear. Any help would be appreciated.

 

[CamperAL]

Hi Jim and all,

I've had trouble with my cord that goes from the RV to the car I tow. I've cleaned up the dontacts going to the car when the turn signal lights wouldn't work. After doing so the began to work again. I am a bit uneasy with this not working and my having to clean up the contacts. The cord is a faily new one and is kept in garage when not in use.

Don't know if your problem is the same but thought I would throw that out for you.

 

[jim4272]

Thanks CamperAl but I've cleaned those up with no luck. And in just the last few minutes I have realized I have no running lights either. But just on the rear. I was preoccupied with the turn signals and didn't notice that.

 

[Utclmjmpr]

Both the fronts and rears have the same source,, start there and follow until you lose the signal..>>>Dan

 

[Mark_K5LXP]

Generally a failure is a single fault. Not that it can't be a case of multiple or cascaded faults but initially you go with one thing is the root cause. So for running and turn lights to have gone out the one thing they have in common is ground. Some poking around with a meter will zero in on it but a bad ground would be the first thing I'd suspect.

Mark B.
Albuquerque, NM

 

[Kirk]

I found a fuse box under the dash by the accelerator pedal and it has a turn signal fuse but it's not blown.

Did you check the fuse with an ohm meter? It isn't rare for a fuse to look OK and still be open. It would also be helpful to know what chassis you have.

 

[jim4272]

Yes I did. I also swapped it with another fuse the same size.

 

[gwinger]

Make sure the lights have a good solid ground. Since its only the rear lights, they may have a common ground to the frame.

 

[John From Detroit]

Some times there is another fuse Had some non working lights found three fuses for the marker lights

 

[gwinger]

Some times there is another fuse Had some non working lights found three fuses for the marker lights

But the fact that's it's both turn and marker. The only thing common is the grounds.

 

[NY_Dutch]

I repaired a Class C with similar symptoms a few years ago. The problem turned out to be a section of the wiring harness that had been chewed apart by a critter. A handful of heat shrink butt connectors soon set it right.

 

[jim4272]

Did you check the fuse with an ohm meter? It isn't rare for a fuse to look OK and still be open. It would also be helpful to know what chassis you have.

Still fighting this issue. It's a Freightliner chassis. My plan today after it stops raining, is to run a wire direct from the batteries negative terminal to the rear lights ground terminal just to see if that makes a difference.

 

[jim4272]

The hits keep coming like an episode of the Twilight Zone. I ran a wire from the battery negative to the rear lights ground. That got the running lights and turn signals working,......sort of. They work right until I start the engine. Then I still have running lights but the turn signals stop blinking, and I only have the left brake light. I can make the turn signals blink by repeatedly moving the turn lever left or right. Immediately after shutting the engine down the turn signal lights will still not blink and the running lights stay on with the key off and the light switch off for a couple of minutes, but then start blinking and the running lights go off. That tells me there's something heating up somewhere and changing when it cools down. I also only have the one brake light when I have the lights on. I have found a relay that clicks in the electronics bay when the blinkers blink. And no it's not the flasher relay, that is under the dash. This is in the rear of the coach. There are 5 identical relays there and I've swapped them around to see what difference that made, which was nothing. BTW when everything is normal the turn signals do operate with the key off.

 

[Kirk]

I have no experience with a Freightliner chassis at all so without being there with my meter, I'm afraid that I can't help. The rear lights would have been connected by the coach builder so this may not be a chassis problem. Can you trace the wire harness to see where it goes and if there are any plugs in it that could be separated to aid in troubleshooting?

 

[jim4272]

I have no experience with a Freightliner chassis at all so without being there with my meter, I'm afraid that I can't help. The rear lights would have been connected by the coach builder so this may not be a chassis problem. Can you trace the wire harness to see where it goes and if there are any plugs in it that could be separated to aid in troubleshooting?

Thanks Kirk. I am out of altitude, airspeed, ideas, and time. I have one brake light, and semi working turn signals that I can work with. Those 5 relays, which are actually just four that I mentioned earlier definitely are involved somehow. I've moved them around and I get some changes. Maybe someone that knows the Freightliner chassis will chime in while I'm on the road, but I have to go with what I've got.

 

[Maddog21]

The ground from the Freightliner frame to RV house maybe bad.
Best place to start is the Freighliner taillight/turn signal box at the end of the frame. (Maybe a plug that goes to the plug for taillight/turn signal mounted on RV house) also test the trailer hitch plug to see if it’s working properly.

 

[jim4272]

The ground from the Freightliner frame to RV house maybe bad.
Best place to start is the Freighliner taillight/turn signal box at the end of the frame. (Maybe a plug that goes to the plug for taillight/turn signal mounted on RV house) also test the trailer hitch plug to see if it’s working properly.

I'm not familiar with the signal box you're talking about, but when I get back I'll start looking for it. Do you know what those 4 relays are that are in the electronics bay behind the drivers side rear wheels? The trailer hitch plug is where I have my tow lights plugged in and they mirror everything that's going on with the coach rear lights.

 

[Maddog21]

Truck manufactures used to put transition points in between chassis and the coach/flatbed/utility beds. Usually a hard plastic box with a terminal strip on the rear of the chassis frame for turn signals, stop lights, parking lights, grounds, trailer light connections. Also some trucks had in the cab behind seat or on the fire wall another point to tie the chassis into the coach/flatbed/utility beds. As part of the owners manual there was often separate schematics/drawing.

Below is a thread of another 1999 Fleetwood Discovery with similar problems.

Discovery New Member, old RVer Checking In - Looking for 1999 Fleetwood Discovery Wiring Info - iRV2 Forums

I'm not sure I am in the right place for introducing myself as I could find no tutorials for this forum, just lots of rules and instructions. I was hoping that someone within this group has

www.irv2.com

 

[Maddog21]

Are you having problems with your front headlights and front turn signals as well or is it just the rear?

Relays may fit the sockets but not be the correct relay for that spot. There should be in the owners manual or on the plastic cover for the relay box guidance of what the relay does and the correct P/N.

Let us know what you find.

 

[TheBar]

Newer vehicles have interconnected wiring. A friend replaced his tail light bulbs with brighter led bulbs. They worked but a couple weeks later he found his cruise control did not work at all. The dealer put original bulbs back in to fix the problem. So any seemingly unrelated changes could cause problems.