My "new" 1983 300 SD has a wire hanging down from the engine compartment that used to go to the caliper, there does not seem to be a problem, yet I don't know what it is, any help? Also, this car came with tank full of fuel that is dyed red, I understand that agricultrial uses this color, is home heating oil the same color? The seller has a number of diesel vehicles, I have no reason to suspect anything untoward. Thanks, toomany MBZ

Its probably the brake pad warning sensor. I have a broken one so it trips the brake warning light (that big orange globe that pops up on the instrument panel on the bottom) but I haven't gotten around to fixing it. Doesn't put you in any danger, you'll either have to fix it or inspect your brake pads every once in a while (which you should do anyways).

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1985 CA 300D Turbo , 213K mi

I agree, that wire would mount to the caliper with a plastic connector end, some were single, some had double sockets for inner and outer pad. The pad would normally have a little white pigtail molded into it that plugs into the wire & shorts to the rotor when your pads are worn and lights the dash warning. If your wire was cut or broken, it will unplug from the harness above and to the rear of the fenderwell in the engine bay for replacement.

I dont know if they dye heating oil, I would tend to doubt it, but red will burn through it just the same as road diesel, really the same stuff just with a dye in it for road tax purposes, just run the tank down to 1/4 or less and the red will dissipate out in the next fill up.

Thanks folks. Not overly worried about said wire, no warning light on dash, it does work, just wondering about next year's inspection. Recent new pads. I did a purge yesterday and noticed the color of fuel with new main filter, I just have a concern about the cetane rating, if any. This is my fifth MB and have done the purge to all, the '83 {174k miles} is the smoothest, quietest yet. In addition, current Benz's include a 1982 {247k} 300D-for sale, and a 1984CD {114k}. I check brake pads and rotors as part the buying process.

Thanks folks. Not overly worried about said wire, no warning light on dash, it does work, just wondering about next year's inspection. Recent new pads. I did a purge yesterday and noticed the color of fuel with new main filter, I just have a concern about the cetane rating, if any. This is my fifth MB and have done the purge to all, the '83 {174k miles} is the smoothest, quietest yet. In addition, current Benz's include a 1982 {247k} 300D-for sale, and a 1984CD {114k}. I check brake pads and rotors as part the buying process.