My 1988 300E sat in the garage for about 5 years. I finally got the fuel system cleaned out and got it restarted and everything seems fine except the 'bulb out' indicator in the dash was on as soon as the car was started and the ABS and SRS lights were lit. I knew the front driver's ABS sensor had its cable cut and I replaced it which put that light out and the SRS went out after driving 60-70 miles. At this point all the bulbs worked but the 'bulb out' indicator was still on as soon as the car started. I resoldered the relay (126 542 01 32) and everything worked but the driver's brake light. I got another relay from the junkyard and then had no brake lights, backup lights, or side markers (either side). About a week's worth of parts, and still no brakes, side markers, or backup lights from any of three relays. Somewhere in here I replaced all the fuses with brass ones.

All the rear lights work properly if jumped from the battery to the appropriate pin on the 10-pole connector under the relay. All the correct bulbs at the connector match the schematic. Even so, I cleaned up the ground contacts in the trunk with sandpaper and re-connected. There is now a brand new Mercedes headlight switch installed. I have about 13.4 volts on pins 8 and 16 on the 16 pole to the relay when the light switch is on. I have about 13.4 volts on pin 15 to the relay when the brake pedal is depressed. I did notice that I have about 7.4 volts when the pedal is not depressed. However, the anti-theft circuitry connects with the circuit just before this point so I don't know if this is normal or not. I did replace the rear antenna with an aftermarket Hirschmann before all this started but there are still no rear stop, reverse, or side lights with antenna either up or down. Both tail lights and all turn signals work properly.

Could I have three bad lamp control relays, should I try a stop light switch, or is there something else I have overlooked? Not sure where to go next.

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1988 300E
1993 300SL
1994 540i

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