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320CAB
22-08-2004, 10:22 PM
Can anyone help. The sidelights and main beam work fine on my 1991 500SL but the dipped lights don't. There is power to both the left side and right side fuses but when either of the bulbs is in the bulb holder the power drops to less than 0.3 volts. The earths seem fine and are shared with the main beam and sidelights. In summary when either side or both sides have a bulb in then the voltage drops away. Any ideas on what else I can check or alternatively does anyone have a wiring diagram ?
jaymanek
22-08-2004, 11:00 PM
Have you checked that there isnt a problem with the switch?? Its very odd that only the dipped isnt working...
Brian WH
23-08-2004, 09:12 AM
Sounds like a dodgy bulb holder, it is shorting out the bulb to earth/itself and causing the voltage drop. :confused:
Ralph
23-08-2004, 09:43 AM
If it was a short the fuse would blow. Somewhere in the positive (non earth) circuit there is a bad connection. Across this connection when switched on, you will be able to measure ~12volts and possibly HEAT. Could be the switch as suggested above. It needs attention, do not leave the dipped beams switched on as serious heat can develop. :eek:

As the earth circuit is OK, by deduction, it is not before the switch otherwise the main beams wouldn't work. Assuming each dipped is separately fused, again it isn't after the fuse box. 95% certain the fault lies with the switch, fuse box or wiring / connectors between. If I had to guess one, it would be the switch.
guydewdney
23-08-2004, 11:50 AM
http://www.autolib.diakom.ru:8001/CAR/Mercedes-Benz/1996/S420/SYSTEM%20WIRING%20DIAGRAMS/5985.pdf

ok its the wrong car - but it might help...
320CAB
25-08-2004, 09:28 PM
Thanks for the help, still not sorted but a few more things to check. I'm out of country for next few weeks but I'll post the solution once I find it !!!!
Cheers
320CAB
12-12-2004, 12:54 AM
The problem was the steering column multi switch. Thanks for your interest and help.
guydewdney
12-12-2004, 12:00 PM
what was it?

edit - colour blind and couldnt see yellow on white... :rolleyes:
Steve_Perry
12-12-2004, 02:39 PM
what was it?
The problem was the steering column multi switch...

S.