Dash board wiring

[Testie]

Does anyone know what the connections are on the plug or socket on the back of the dashboard (14 pin)?
74 SL350.
I'm having trouble with the dash lights because of a shorted bulb but somehow the plug , which can be any oriention, is mixed up. Because the steering wheel is in the passengers side at the moment I am without the car.
Please help if you can. I have the correct wiring diagram but don't want to pull the dsah apart the see how it connects behind the plug.
Col.

 

[WGB]

Unless your circuit board is damaged it should only fit one way.

Do the pictures on this help at all.

http://www.topklasse.org/forums/showthread.php?t=3286

If you go to the bottom of the posting there are pictures of the rear of a 6.9 cluster.

Bill

 

[Testie]

Thanks for the photos but
I had already searched through them. great photos but there seems to be no way to orintate the plug. it fits anyway There must be a key broken-the only safe connection I can find is power on one pin in the plug when the light switch is on. Surely if I can find the light pin to the reostat then the rest must be correct. It appears as though I have lost an earth so I will carefully check to see if I can find a brown wire in the plug.
Any other hints numbers etc appreciated
Col

 

[Styria]

Hi Testie, I am somewhat confused because, as WGB has pointed out, there is only one way that the plug can be re-fitted. Unless, of course, you have a break in the board itself - where the plug fits. If broken, and you cannot connect the plug correctly, i.e. connector to connector for a given function, you will indeed be in trouble. I have some boards spare that are not damaged. I guess I am understanding your problem correctly, but if not so, please don't hesitate to reply. BTW, Bill does a great job with his description of many tasks that he has carried out since he acquired his 6.9 from the previous owner. In keeping with suggestions by some, Admin. has re-directed Bills thread to the 'ARTICLES' section.

 

[Testie]

Thanks for the replies. I have checked and drawn every connection and wire colour so the only problem I have now is to work out how the plug fits in the circuit board socket. I take it that there should be a pin "D" shaped in the middle of the plug. It does not exist so now knowing were each wire goes in the dash board I should be able to mate them up. Because that "D" is missing the plug can go any of 15 or so different ways with varing resultsThe rheostate is shot and I have not been able to precure one so it will be bridged out for the time being. Full voltage on the illumination won't hurt and is probably the possition it stays in anyway. A new plug would fix it permanently but what a nightmare to change all those little pins over.
I will give you a progress report when I get it correct. I am fairly confident that if I find the earth pin and the dash light pin then all should be OK.
Col.

 

[Testie]

Well that didn't work like I would have hopedI will have to pull the plug apart and connect each wire seperately. When connected as I thought the low fuel light came on not the dash lights. Next weekend as I am going away not looking forward to it.
Col

 

[Testie]

Still blowing fuse on right hand parklight and dash lights. I give up
Seems to be ok untill the dash is hooked up it must be in the aux. wiring for the lighting on heater or gear selector. Looks like the car will stay where it is for a while, my blood pressure can not stand any more.
Col

 

[Michel]

Might have to call an electrician Col.

Keep that blood pressure under control mate.

Easier to blow a fuse on the Benz then for you to pop one off

 

[Testie]

Thanks Michel, might be a bit hard to get a auto electrician to make a house call.
But like you said I don't particularly want to blow my fuse. Might just have to put the dash back together and the steering wheel back on and not turn the lights on ever again. It must be outside of the dash and maybe in the lighting switch? Don't want to tackle that one either!!
I will keep you posted once my pills start working......
Col.

 

[Michel]

Thanks Michel, might be a bit hard to get a auto electrician to make a house call.
But like you said I don't particularly want to blow my fuse. Might just have to put the dash back together and the steering wheel back on and not turn the lights on ever again. It must be outside of the dash and maybe in the lighting switch? Don't want to tackle that one either!!
I will keep you posted once my pills start working......
Col.

I know of a couple of electricians who do house calls.

PM SENT

 

[Testie]

Put the car back together , sort off, and took it to an auto spark. 10 mins.to find a burnt bulb holder behind the heater controls. All the hard work had been done !!
Finally found one at a wreckers, the T1 lamop holders are unavailable from any of my parts suppliers so if you are wrecking a w107 keep the lampholders!!
I haven't finished putting the car back together yet but the instrument panel does not seem to want to go back properly. It seem to want to sit out at the top. Next weekend I will try to figure out what I have done.
Col.

 

[Styria]

Hi Testie, the instrument panel can be a bit of an awkward fit. Generally, some careful wriggling (start to feed it in on the left hand side) and perhaps even a slight smear or spray of lubricant (INOX, Vaseline) can help to push it back into place. Regards Styria

 

[Testie]

Thanks Styria, tomorrows job. I will keep posting until it is completed.
Col.

 

[Oversize]

Excellent news! Try some silicon spray on the seal, but be careful not to get it everywhere. It's still less messy than vaseline. When you're up n running, post some pics of your lovely looking car in a thread you can dedicate to it!

 

[Testie]

Finally gotthe lghts working but putting the istrument panel back in is not going well!! The bottom goes in nicely but the top sticks out 1/8''. I tried silicon but even with the strip along the botton of the panel left off it won't go back at the top. Break time. Any further sujestions , is the oil line or speedo cable likely to cause problems?
Col

 

[Testie]

Try the photo again!

 

[Testie]

Wrong photo. I'll try again! Is the instrument panel suposed to sit out fron the dash ?

 

[BenzBoy]

No - it should not sit out from the cowl like that. It would seem something is not sitting correctly behind it - maybe the speedo cable has come too far through the firewall and need to go further back?
Regards,
Brian

 

[Oversize]

No it's not. Quite often the seal is positioned incorrectly, or can become misaligned. It should sit up against the first ridge around the cluster housing. Yes the speedo cable, oil pressure pipe and all the wiring can prevent the housing sitting correctly, so make sure it's all neat and tucked away. You may even need to remove the underdash trims to guide it all back into position. Good luck!

 

[Testie]

OK here I goagai! Wish me like
Col