Car is a 1983 240D.

To make a long story short, when I took out the radio last year, the #1 fuse started blowing. Moving the wiring around behind the dash and shifter seemed to fix the problem. Now, the damn stupid freakin' thing has recurred (at the worst possible time, while driving to middle of nowhere, western Maryland), so I'm minus interior dash lights and the right tail light, I think license plate lights as well. I suspect a short in the dash lighting wiring somewhere -- will tear into the dash on Friday.

Three questions:
(1) Can anyone post a wiring diagram for the dash lighting, and the other circuits controlled by the #1 fuse?
(2) What color wire runs the dash lights?
(3) Is there any convenient point where the entire dash lighting circuit (gauge light, window switches, HVAC controls, etc) can be easily disconnected from the car without affecting anything else? I'm willing to live w/o dash lights for a while, and this should also help isolate the problem!

Thanks in advance, and Happy Thanksgiving!

Check the media forum. You probably messed up the gray/violet wire on the radio. There are at least three fuses for the radio: 1, 2 and 4, I think. One controls just the lights for the radio - yes, you can pull the radio power fuse from the OE radio+harness and the radio will still light up.

The gray/violet is the dimmer circuit from the rheostat. It can get overlooked in radio installs since they're commonly done in the day, with the headlights turned off, so it looks like a ground wire or other "unused" wire until you turn on the headlights and the fuse blows.

Thanks.

Pulled the radio again (it's the original Blaupunkt two-knob), but some spaz had messed with the wiring behind the panel before I bought the car. There were thin two bare-ended wires -- red and grey/black. Insulated the ends, and now all's well for now.

BTW- my cig lighter appears to be disconnected. What wires are supposed to connect to the tabs on the ashtray bracket? I didn't see any stray wires that would have been thick enough to carry current to a lighter socket.

The lighter has a pig-tail connection that is "interrupted" between the car harness and the ashtray to provide power for the radio. But the metal is also part of the circuit and the ashtray needs to be fully open in order for the lighter to get power. The source wire may be black, then red downstream of the connector.

Some info here: http://www.peachparts.com/shopforum/car-audio-multimedia/298631-new-stereo-install-1979-240d.html

Here (long, lots of links, pics and troubleshooting): http://www.peachparts.com/shopforum/car-audio-multimedia/284681-240d-frying-radio-fuses.html

Some diagrams here: http://www.peachparts.com/shopforum/car-audio-multimedia/154476-keeps-blowing-fuse-little-help.html

Looks like someone snipped it off after the radio -- I'll add it back

You may want to fish around a bit. It's an odd set up. There should be a 4-wire connector that goes to the radio (switched, unswitched, ground, dashlights). But two of those wires trace back into the dash and two come from the lighter connector. At least the 300's had the 4-wire with the solid state radio; the 240's may only have had a 2-wire; or possibly a 2-wire connector and a loose wire for dimmer. It depends on the OE-radio.

If somebody was cutting, they'd probably cut the 4-wire directly behind the radio and not at the lighter. I'd anticipate the lighter 'should' be a plug-and-play unless they really messed with the wiring, which is always a possibility.