Problem:
1. The high brake light on my SL500 will not work. I have changed out all six bulbs.
2. Cannot find a fuse for high brake light?? Or frankly any brake light. Does anyone know what Fuse controls this and in which box-trunk or in engine compartment.
3. Brake lights only come on when the key is turned and power is on or car started.

Questions:
1. Shouldn't the brake lights come on even if the key is not in the ignition if you step on the brake pedal? Does on my wife's Lexus.
2. Any idea as to where the fuse is for brake lights including the high Brake light on the trunk lid.
3. Thoughts as to why my High Brake light does not work.

Thanks for your help.

1. it's not a lexus : ) Seriously, it's normal.

3. The problem is most likely where the connector plugs into the center brake light or where the wires are routed up to the trunk. They go through some rubber loom at the hinge. I have heard this is a common source of trouble. Get a voltmeter, start probing from the connector back and see where you are no longer getting power.

1. Brake light operation is subject to manufacturer's whims and logic. VW brake lights work w/ or w/o ignition on, Mercedes, in my experience don't.

2. There is not likely a fuse for that 3rd brake light. Most likely it is wired back to either the left or right side taillight and just gets power from there. Look at the color of the wires where they connect to the 3rd brake light and see if you can find the other ends of those wires at the connector at one of the taillights.

3. I would first suspect the wiring harness that runs up along the trunk hinge. Opening and closing trunk lids over the years will actually break the wires in the harness. This is not an unusual problem.
You could also have a bad connection at the light on the trunk, or at the taillight where the 3rd brake light is connected.

Hope that helps.

__________________
Fourings

84 Audi Coupe GT with Turbo engine, EFI (buh-bye CIS), Jamex seats, Koni's/H&R's, e-code lights. 210k and counting.
1992 Anthracite 400E, 161k, "Grey Ghost".
1986 VW Quantum Syncro, 192k, gone to the crusher in the sky.
1989 300TE 172k. (Was mine, now also Mom's car)
72 280SE 4.5 (Mom's car)

Thanks for all of your suggestions. I have disconnected the third light and used a voltmeter but did not get any signal at the connector. I need to look deeper and try and track down the wires as suggested.

Thanks

The wires always always always break inside the hinge flex area.
Rewire the power and ground using a hi-strand count flexible wire
and run it from behind the trunk bulkhead to the center of the trunk lid.
repairs made in the hinge area or close by will fail days later.
All will be fine afterwards.
Dr.D

__________________
Dr.Diesel -
Shop Foreman
Master Guild Mercedes-Benz Technician.

Think the dealer is expensive? Do you know how much it costs to train a dealer tech? Or buy the required MB special tools to have on hand?

Thanks for the Help!


I have a 1998 SL500 and the bake light was not working (no power). The problem was the wiring inside the rubber boot that connects to the trunk hinge and trunk lid. One of the wires was disconnected from a previous repair. I also found the yellow plastic switch that turns the trunk light on and off.


Thanks again...

I have a slightly different problem. One bulb is out in the trunk lid and I do not know how to remove it. I have a trunk lid from another car and tried to practice on it but ended up breakingshattering the whole thing in the process. Any one have a suggestion how to remove that 'strip" of lite without damaging it? Bye the bye, is it a "bulb or an LED of sorts? This is a '95.

Thanks, Steve