Running lights GONE

[SoCal Solera]

I got 18000+ on my 2010 sold as a 2011 and my running lights just went out but isn't a fuse
While working on it they came on for a minute then off again.. I'll check that wire connection
John

[Jtnorton]

I had similar issue (along with many other issues I have written about). Mercedes man called FR dealer who called FR rep and he seemed to know where the problem was and why and gave the mechanic a fix. FR on installation of the body had use screws too long and in time they chafe through the wires that are behind the right rear stop lights. Need to remove a panel in rear compartment to access. Mechanic was able to fix and installed shorter screw as per FR instruction. Question: why doesn't FR put a headsup and recall to all its dealers? Lots of money being spent on diagnosis when they seem to have the answer. Go figure. Ugh.

[SoCal Solera]

Thanks JT
Is it something we can do ourselves ?

[Jtnorton]

Originally Posted by SoCal Solera

Thanks JT
Is it something we can do ourselves ?

It was way above my head. Sorry.

[peterfinurke]

I'm on the road in Northern CA & have the same problem, running lights and tail lights out, brake & turn lights working.
I went through the Mercedes fuses (all). The forum fix is another secret fuse box in the Sewer/Electrical panel access.
I have looked all around the sewer connection, left rear access door, & have not found any markings as noted.
What compartment do I look for this "Sewer/Electrical" access? I have a long drive back to Louisiana & would like to have all lights.
Thanks to all for your input.

[papap]

There is a shelve right above the sewer connections. You have to remove the plywood in the back of shelve. Fuses are behind it.

[peterfinurke]

Thanks papap, I found the module. My panel had no label.
All fuses were good so I unplugged the lower left plug which had a pin labeled "running lights" Turned my lights on & metered the output, nothing. Just to check there is 12v power to the module & I get an output on turn signals and aux. etc.
So I suspect the module itself or what ever triggers it.
I couldn't get it out, took it loose but wires too short & that expanded foam held it back too.
I also took the right rear tail light inner cover apart looking for shorted wires from long screws as someone else had experienced, but nothing.
So all fuses on the Mercedes & FR sides are good, I meter them all for continuity. Maybe a bad splice somewhere. I'll drive back daylight only & maybe once I get home to my shop I'll uncover the culprit.
Of course, if you have any additional ideas, I'll be here for 2 more days.
Thanks again for the help!
Peter

[TeresaInCAL]

Peter there is a really good RV place in Linden, don't know how far it is from where you are. The name is Whitaker RV 209-877-7878.

[Freightliner]

That plug the left lower corner of that control is the INPUT side of things. The problem some of us have experienced is in the contact of the connector that plugs into the control board at that location. With the Solera running check for 12v coming out of the running light wire (brown iirc). For what ever reason there seam to be a problem with the connection at the wire in that connector. I soldered mine and have not had any issues since.

[peterfinurke]

It looks to me that the plug goes to the trailer connector & the control supplies the power. I'm getting nothing out of the control board on running lights. Other outputs are there, e.g. auxillary on that same output.
That is why I suspect the controller or what ever input from Mercedes tells the controller to supply voltage to that output.
Does anyone know where the controller gets it's input, i.e. where the connection from Mercedes to FR might be?
If I knew about where to look, I might be able to put a toner at the controller & trace it back to the Mercedes wiring.
Thanks

[jamiller45]

I would check voltage at "PARK IN" for the MB signal. If you get voltage there, then make sure all fuses are good on the controller. If there is no input voltage, then I would go to the plug on drivers side, above spare tire, toward rear of vehicle. I have added a pitcure of our wiring diagram of the harness. I would be leaning more towards a short somewhere in the output circuitry though. If the "RUNNING LIGHTS" shows a voltage of or around 1-1.5, instead of 12+, there is a short in the line. I can also send this as a pdf if you would like to pm me your email.

[peterfinurke]

I just got to a printer and the image is not clear, is there somewhere I can download the original pdf file of the controller?
The "Park IN" voltage you mention, is that on the board? I have 12 volts at the two lugs coming into the controller, just got nothing out where the running lights plug attaches. I'm assuming the plug itself is the output to the trailer wiring.
Peter

[jamiller45]

see last sentence of my post above yours

[peterfinurke]

send pdf to peterfinurke@gmail.com
Is "Park IN" on the controller? I got under my MH & found plugs on right & left sides that are coded brown, look like running light outputs.
Do you know where the connection from MB to FR would be? Which of the 3 plugs on the controller is input from MB, i.e. top, left, right?
thanks Peter

[papap]

Would like it sent to me also. Just incase I ever need it. papap@att.net

[jamiller45]

The connection points for most of the wiring from MB to FR is in 2 plugs mounted on the crossmember behind the spare tire.

[SoCal Solera]

Still having problems just got back from Oregon Star Party and could only drive in the daytime...
I REALLY get the feeling this is a loose ground wire, the lights will come on now and then but not for long and do not blow any fuses
Now back... I'm going under to have a look
John

[peterfinurke]

Can someone post the PDF file on the controller. I have checked & cleaned the 2 plugs over the spare tire, but now I need some guidance in tracing voltage.
Thanks Peter

[jamiller45]

Peter- did you not get the email I sent you with the pdf as you requested? i sent it to you and papap

[peterfinurke]

I got the first attachment which was not a PDF file & when I tried zooming in, it was too blurry to read the text.
No PDF received, I am on the road, so that may be a problem.
Thanks Peter