1980 450sl electrical problem

Have 1980 450sl w/ new battery - all fuses in proper order... when car is on (and running great) many electrical items don't work and certain things on dash aren't working - i.e. gas gage isn't registering, power windows inoperable, and brake lights don't work??? but other things work fine like the speedometer, temp gauge, radio, tail lights, head lights, etc. Is there something between the fuses and battery which is shorting potentially or an alternative fuse???

Thanks - Mark

[MikeTangas]

Power window fuses aren't in the main fuse box, they are in a separate box (or boxes) somewhere on the firewall.

As for the brake lights, did you verify that the brake light bulbs (single filament) aren't burned out? Did you also check the function of the brake light switch? The older brake light switches do have a tendency to stick. On the 4.5 the switch would stick, then slowly engage giving very delayed brake lights. replacing the switch cured that problem.

Fuel gauge could be dead, or the sender dead or the electrical lead to the gauge disconnected, or, or, or....

While you are looking at the fuses, just go ahead and replace everyone in the main box. They may look good, yet in fact be bad. Change them all, it isn't an expensive proposition.

I would agree with your comments but my response is that all of these things happened at the same time - i.e. "now there working... now there not!" so the same source would seem to be causing all the the problems. Thoughts??

[stevebfl]

Since brake lights, gauges, and power window relay are all powered by the #10 fuse, I'll give you three guesses where I'd go first.