Brake lights aren't operating

andymcgill · 07-10-2016, 06:31 PM

I have a MB 2010 TDCI Mondeo. The left and right brake lights aren't working, whereas the upper light is. The lamps are OK. I suspect the control module, but I can't locate it. According to Haynes it is on the passenger fuse box, but I can't find it. In theory it should be near or on the tailgate as it is CAN controlled. Does anybody have the wiring diagram or schematics? Much appreciated if you do.

foxtrot3 · 07-10-2016, 08:26 PM

Hi. Did you replace the globes to check that the lamps are OK or is it because the park lights are working? Stop/tail globes have 2 filaments (one for each function) and it is quite common for one filament to fail and loose one function. Cheers MD

andymcgill · 07-10-2016, 08:55 PM

I did a visual and ohms test on the lamps. Both are OK. Tomorrow I will pull the passenger fuse panel out and see if there are any electronic modules hiding within it.

cobrin · 07-10-2016, 10:37 PM

Quote:

Originally Posted by andymcgill

I have a MB 2010 TDCI Mondeo. Does anybody have the wiring diagram or schematics? Much appreciated if you do.

Here mate from my book Ford Mondeo Apr 2007 to 2012 seems pretty straight forward.

andymcgill · 07-10-2016, 11:02 PM

It appears straightforward, but doesn't show the control module location. It only shows the fuses. I have the same manual as you.

andymcgill · 07-10-2016, 11:05 PM

As I said previously, I will pull the fuse ***'y out tomorrow and see if the modules are inside.

rondeo · 07-10-2016, 11:50 PM

I have a "'Ford ETIS offliner'' in Russian language. I'm struggling with the software but I can view images of the wiring which is in SVG format and translate captions in Google. The whole thing is about 9ooMb.

I found the correct stop light diagram. It doesn't show a module for the stop lights, just the CJB or GEM with a rectangular box labelled ''internal HW'', I take to mean hard wired.

andymcgill · 08-10-2016, 12:29 AM

Hi Rondeo,
What you have sounds very interesting. Thank you, but I may need some translation.

andymcgill · 08-10-2016, 12:32 AM

It does appear to be the GEM (Generic Electronic Module).

cobrin · 08-10-2016, 12:46 AM

The Centre High mount Stop light is run off a different system #30 the controller is found in the GEM (passenger fuse box) anyway it works so it's pointless going there. I'd be looking at the Brake Switch and Brake Position Switch Chapter 9 Section 15.

2 Engine Fuse box - F17 & F18 -Power supply to the GEM
5a Passenger Fuse box - otherwise known as GEM
22 Lighting Switch Control Unit - headlight switch on the dash Powered by F33 in the engine bay fuse box
24 Stop light switch - At the brake pedal (so is the Brake Position switch)

andymcgill · 08-10-2016, 01:12 AM

Give me the old days when everything was easy. You mentioned the brake switch, but this must be working for the upper light to work. I get the impression you have had a lot of experience with the electrics.

cobrin · 08-10-2016, 01:42 AM

Enough experience on Automotive to get my way around but background in Mining for nearly 20yrs helps - HD Plant Mechanic.

I can't take all the credit it's a common problem with plenty of other vehicles and rear lights failing but centre high mount still operational.

andymcgill · 08-10-2016, 01:46 AM

Is this a redundancy thing, so that if one system fails there is a backup?

cobrin · 08-10-2016, 03:13 AM

I'd say exactly that, yes.

rondeo · 09-10-2016, 12:15 AM

Stoplight pinpoint tests:

http://workshop-manuals.com/ford/mon...ing/stoplamps/

andymcgill · 09-10-2016, 09:30 PM

Thanks Rondeo,
That is quite helpful. Is there any chance of sending all electric info out of this manual for future reference and modification? This site must be secure as I can't access the wiring diagram link.

sailaway · 10-10-2016, 08:55 AM

Quote:

Originally Posted by andymcgill

This site must be secure as I can't access the wiring diagram link.

No problem here using Win7 and Google Chrome.

rondeo · 10-10-2016, 08:50 PM

Quote:

Originally Posted by andymcgill

Thanks Rondeo,
Is there any chance of sending all electric info out of this manual for future reference and modification? This site must be secure as I can't access the wiring diagram link.

Not sure what you mean. There are no wiring diagrams, just electrical fault finding which refers to unavailable schematics. You can save the web pages from your browser if you want them offline.

The free Russian software I can no longer find. People are selling it.
The idea with that software is you click on a connector in the schematic and it shows the location in the vehicle and the pinouts. Very nice if it were in English and wasn't buggy.

Cheers.
пусковой двигатель !!

rondeo · 12-10-2016, 08:33 PM

How are the lights?

andymcgill · 13-10-2016, 10:44 AM

Sorry, forgot to tell you I found the fault. It was a poor connection on the GEM. The lights are ok, but there is a warning light on the dash showing a rear ender. That maybe the forward warning is disabled. Thanks for all your help.
The link I can't access may be due to my using an iPad.