No dash lights on 230 TE W124 1988 - Electrical problems...

[sysengb]

Help! I've got no instrument cluster and switch lights on the dash, no number plate lights and no headlamp warning buzzer on my newly aquired 1988 230TE W124.

A look at the manual pointed me to fuse no. 3, as all of these functions are on that fuse.However the fuse is ok and i still have parking and tail lamps working and these also hang off fuse 3.
I checked the number plate bulbs and they're ok - no voltage present at the bulb connector.
Anyone come across this before?
Also can anyone recommend an independant MB garage in the north of Scotland?
Thanks

 

[sunil sood]

No dash lights on 230 TE  W124 1988

dont know for sure but could it be a faulty relay or perhaps a faulty earth-if you have a haynes manual,then look at the wiring diagrams,they some times tell you where the earth points are located.
if this is a dead end ,then it may be a loose or open connection in the circuit but do not where this could be.it could be a broken wire in the circuit somewhere.

 

[Andy]

No dash lights on 230 TE  W124 1988

Hi

I would first check that the dimmer switch on the dash is fully on. The other thing that are problamatic is the potentiometer at the back. The thing which dims the dash lights. These play up. If when you operate the dimmer and the dash lights flash on and off. Then replace it.

Hope I have been some help.


Regards

Andy @ www.mercedesservicing.com

 

[sysengb]

No dash lights on 230 TE  W124 1988

Thanks for the pointers guys.
Further investigation reveals that the dimmer is OK and after removing the instrument cluster and testing with a multimeter, the problem is that there is no 12V feed from the lighting control unit when the lights are on.Presumably a busted wire or a duff control unit ?  Is
the lighting control the long black relay behind the fuses? I wonder if any of you have changed one of these?Merc. want £78  for a new one !

 

[sunil sood]

No dash lights on 230 TE  W124 1988

do not know if that is it but you could chck with eurocarparts-0208956-5000, or german and swedish as my experience is they usually beat the dealer on similar parts,

 

[sysengb]

No dash lights on 230 TE  W124 1988

Problem solved

After taking the car half to bits the culprit was found.
The wiring plug at the back of the light control switch was very loose - just about to fall off in fact.Reseated
this and hey presto -  dash lights,number plate lights
and lights on buzzer all sprang into life.Well chuffed.
Thanks for your help Sunil and Andy.