Reverse/back up lights not working

[edgewant]

Anyone had this issue and have any insight.

I’m on the road so am reluctant to do too much.

Checked all the fuses and all are good. Checked for ground on one of the four lights and it checks good. Checked one of the 4 bulbs and it’s good.

Didn’t test relays but plan to when I return home.

Found the supply wire coming out of the firewall from the TCM but haven’t checked it for 12v when in reverse.

Contacted Freightliner and they mentioned checking all the ignition fuses in the box in the compartment below the drivers seat. Every fuse checks ok.

Any thoughts.

[ceedog]

In my 2011 Berk there are fuse banks in the electrical bay that aren't listed in the manual.


Some of the circuits for the rear of the RV are fused there.

[Maingler]

Freightliner only supplied a 10A circuit and it wasn't large enough to feed all the lights.The back up signal from Freightliner feeds a relay in the front elctrical comparrment and a fused circuit from the Berkshire fuse panel feeds the lights.

[edgewant]

Originally Posted by Maingler

Freightliner only supplied a 10A circuit and it wasn't large enough to feed all the lights.The back up signal from Freightliner feeds a relay in the front elctrical comparrment and a fused circuit from the Berkshire fuse panel feeds the lights.

Any idea which Berkshire circuit.

I just tried putting 12v to pin slot 87 on the reverse lamp relay circuit and no lights. I’m beginning to think it may be a splice that has worked loose in the rear cap.

There’s one big bundle of splices in side the cap. I believe it splices the four tail light circuits into the freightliner wiring.

[Maingler]

Ill look at it tomorrow and let you know where to look.

[Maingler]

15A trunk light fuse in Coach Fuse Panel feeds the rear lights and I attached taillight harness. Relay in rear should be located rear passenger side. Blue wire is back up chassis signal to relay.0610-500101.pdf

[edgewant]

Originally Posted by Maingler

15A trunk light fuse in Coach Fuse Panel feeds the rear lights and I attached taillight harness. Relay in rear should be located rear passenger side. Blue wire is back up chassis signal to relay.Attachment 241932

Thanks. Are any of the unmarked relays in the compartment below the drivers seat involved?

[Maingler]

This will make more sense. There should be a 15A inline fuse at the batteries REV 14 PUR runs to pos 30 on reverse light relay.

[edgewant]

Found the relay and it checks good. It’s in the most aft compartment on the passenger side.

Looked in chassis battery compartment and found one 20 amp in line fuse.

Is that the right one?

[feedfold]

PDM panel in the inverter box, it fixed mine.

[feedfold]

I wouldn't get backup camera also when my backup lights didn't come on.

[edgewant]

Dude.

What year is your motorhome?

Mine looks nothing like that!

[feedfold]

2016 34qs

[edgewant]

Mine is a 2013 390RB. It has 4 back up lights. Apparently a 10 amp circuit was insufficient, which I get, so FR added a circuit.

Unfortunately it’s not something they share unless you have issues with it.

Just wish they would provide a complete set of schematics especially when they circumvent something that Freightliner has provided.

[Maingler]

You have an older unit. Is it a purple wire coming off the fuse?

[edgewant]

Originally Posted by Maingler

You have an older unit. Is it a purple wire coming off the fuse?

The 20 amp fuse in the chassis battery compartment has a red and a white wire.

[edgewant]

It’s a purple wire feeding pin 30 on the relay.

But I still haven’t been able to locate the in-line fuse.

[edgewant]

Is this the fuse for the backup light circuit?



If so where can I get a replacement?

[Maingler]

Thats it, is there power on the blu/wht? Look up short stop or mini breaker. NAPA carries them.

[edgewant]

Originally Posted by Maingler

Thats it, is there power on the blu/wht? Look up short stop or mini breaker. NAPA carries them.

The blue/wht wire does indeed have 12v on it. The fuse circuit tests ok.

I also tried jumping from pin 30 (purple) on relay to the pin87 (orange ). No reverse lamps. So now I wait till I get home in a couple weeks to look for a bad splice.

Thanks for all your help.