Hello community!
Here is the situation what I need a bit of help. The car in question is Ford C-max 2011, 1.6 diesel, manual, nothing special as options, regular radio  and it has automatic DRL.
The car external lights turn on even the light switch is at position zero and you open the door, and also the instrument cluster come to live.
The owner by mistake forgot about that and try replacing number plate light. During the process has been created short circuit.
Because of that, the license plate voltage has gone and also instrument cluster is off. I mean totally off - no temperature gauge, no fuel level, rpm counter.. Nothing!
When on contact, or engine run - totally off.

Please, before you laugh that I can not find one fuse, let me continue.

First, all fuses over the GEM module was checked and also F69 - all fine. Then I found the electric diagram for Focus MK3, what seems to be the same:

From BCI/GEM plug C8 pin 16 power suppose to be supplied to pin 3 on the cluster via violet-red wire.
I removed the instrument cluster, and sure enough the wire cable was the same color and no power to it. 

Here I would like to point out something that I found really odd - checking on the wire diagrams did not find any fuse related to number plate lights.. I guess inside the GEM module there is some fast self recovery PCB fuses but didn`t find any on fast check when I take the PCB out of the cover.. Anyway...

For me was odd to have perfect connection from C8-pin 16 to 12V main supply and nothing up to the cluster plug.
Cluster`s plug have the following pinout:


 

 

C8 plug looks like that:
 

 

Yes, I was suspicious to what degree my diagram was fine so I register in Ford and got that diagrams by it`s VIN and they are exact 1:1 match to what I have anyway..

And here is what really pi$$es me off in that situation : when I open the plug C8 there is NO pin 16 !!! Just empty socket hole. 
On the same C8 plug, there is VT-RD (violet-red) cable but it goes to pin 3 !!?!? And when I try conductivity test there is no connection in between it and pin 3 cluster plug.
So why on earth there is F69 and power to missing pin, and why all diagrams point to something that is not exactly as it is build. Even the car users manual stated that F69 is the cluster power supply.

To answer your question in advance - the cluster and all was working flawless priory that lamp mistake happen. No burned pin, no cable or socket was tampered with..
There is OBD connection to the BCM/GEM and the only error is some front left door ajar something is not closed. System was tested with Forscan software.
Also, there are some modules more that the program can not access (ACM, IPC, FCDIM). Not sure because they are missing as never fit, or that they should be present but there is no power to them.

Will check again when I have time all fuses and will try to figure out where that violet wire end up, but if anyone have some thoughts will appreciate it!

Thank you

 

 

I've not read the full post (I only had an hour 🤣)

Quick answer is remove bulb(s) from the number plate lamp holder(s)

Disconnect the car battery negative lead. Wait 15 to 20 minutes and then reconnect the battery. Check that every thing is working, except of course the number plate lights. Fit new bulb(s) and retest.

Even though I suspect I'm urinating in the wind, a blown or wrongly fitted number plate bulb will not blow the cluster.

But the normal cluster solder breakdown fault will or a GEM full of water

6 minutes ago, DaveT70 said:

a blown or wrongly fitted number plate bulb will not blow the cluster.

The number plate lights and the back lighting of the instrument cluster share the same output from the GEM/BCM. If there is a short-circuit of the number plate light the GEM will turn off the supply until the fault is cleared. This should happen on the next key cycle after the fault has gone, but sometimes the GEM needs to be rebooted with a full power down before it will turn the supply back on.

Then I stand corrected, said the man in the orthopaedic shoes.

We're piddling in the wind though, you know that don't you?😄 

Thank all of you for your fast replays , and in general suggestions!!

All mentioned so far assume I lost dashboard backlight which is not the case at all..  And also as I stated the supply fuse give power to NON existing pin, which is against any electric diagram I found for that model. Is not burned, broken or damaged.. It physically do not exist in plug C8 (F-for the diagrams) !

There isnt any water damage to the GEM, bad solder points in the dash, burned pins or socket.. and so on typical for that model.. Just no main cluster power supply. And that is measured straight on the cluster's socket. It is exactly same with cluster connected or not. By far that shouldn't matter if there is straight line to 12V anyway judged by the wiring schematics.

Yes, battery been removed for a while, ignition cycles given...non of that brought back the MAIN power! Yes, the numberlate lights are working now just fine as all other lights. The bulbs are correct one too.

Crank sensor, backlight control, MS can lines and signals ,including dashboard ground , all are there over the the plus's pins. The only one thing missing is the power supply over pin 3 ..

And also as I mentioned at the beggining, the only error message what is stored in the GEM is about some front left door not closed(ajar...).. Norhing more or less...And I doubt that is related.. Well, unless the car during manufacturing did not get the right wire loom (because of that missing pin). So then someone jut bypass the power supply from there to some other module or line and car went for sale..

Just to give some closure on the topic.
After finding some spare time today, I checked once more that pin 3 inside instrument cluster`s plug against all pins that are located in the BCMi module.
And once again unfortunately did not get any positive signal on conductivity test.
This time I remember to take a picture of that mentioned C8 plug:



As you can see that pin.16 what I talk about in my previous posts is just... missing...
That`s why , I decide to make a bit more drastic measures. That wire going from the dash to who knows where was cut:



and new "bypass" one was installed up to the GEM module:



That use the up mentioned Fuse 69, so in some sense the connection currently is as supposed to be. (seen on the wire diagrams).
Due the fact I do not have any spare pin or pin with wire as that one:


 

it will be with that bridge-fuse holder and later on at some point when get one will be fixed.
As for the result, it was as predicted:

Now car is again usable which is important I think...
And I don`t plan to investigate further where that original wire was messed up, and why..

Thank you for participating in the conversation!