The symptoms:
Left turn signal works fine, both ends.
Right turn signal inop, or flashes very dimly, but can hear the flasher clicking.
Turn filaments on both ends blink very dimly.
If I turn on the headlights I get marker lights on both ends, and the rear turn filament lights up dimly.
If I turn on the right turn signal with the headlights on then turn filaments on both ends light dimly but do not flash, and the indicator comes on brightly.
Now for the real wierdness.
I discovered this by accident. With the key off, if I turn on the headlights, or even just the parking lights, and turn on the right turn signal it makes the whole ignition bus flash. And I mean the _whole_ ignition bus including the glow plug controller.
If I have the engine running with the lights and right turn signal on, then turn the key off, the engine keeps running until I either turn off the lights or turn off the turn signal. The rest of the electrical system seems to die quietly, but the engine keeps running.
The grounding wires for all of the turn signal light fixtures seem to be good. I have not been able to test them with a continuity light or a multimeter, but the wires look in good condition and have clean grounding points.
My mechanic said it could be either the turn signal switch or the headlight switch. I have tried replacements for both switches to no effect. I suppose the next candidate is the ignition switch, but replacing that is a job I REALLY don't look forward to.
Does anyone have any idea what could be causing this? Please help before I pull out a: my hair, and b: my entire electrical system.
AP