I am stumped as I have run out of ideas. The car is a '88 240 wagon, 5 speed with AC with no pw or cc. I added a big tach and small clock.

Problem: The instrument panel lights do not work at all. When I turn the rheostat switch on, the green signal indicators stay on (signals work fine)and the tach drops several hundred RPM. With the rheostat off, the tach is fine. Everything else works fine but at one point everything worked fine.

What I have done: I installed new bulbs. I replaced the ignition switch with a new one. I swapped the rheostat and headlight switchs with known good ones from my '91 240. I cleaned the contact points on the panel. I checked for unattached wires. The only ones I could find that were not attached are a blue one for the big clock and a yellow/red one for the auto/od indicator. The harness looks fine. The only aftermarket addition is a stereo.

It is a problem I can live with if need be. However I would really rather have everything work. The obession to find out what the problem is becoming overwelming. What am I missing?

Thanks, Bob