Turn signals, pwr windows, 3 guages dead, HELP!!

[rickjordan]

I posted this on the diesel forum as well.
My '83 TD have developed an interesting electrical problem. A fews days ago the RPM gauge started fluxuating(sp) wildly, swing as high as 6,000. Then other times wouldn't read anything at all. At the time I figured, it's the sensor (black plastic cap thing on the wheelwell) I just figured I'll get to it when I can. The next thing I know the fuel level, water temp, all 4 pwr windows, and the turn signals, stopped working. The hazards work, but the left and right turn signals don't. Also, once you start the car, the bat. light stays on until you rev the engine a little. I replaced the alternator (Bosch) back in April. I haven't had the chance to troubleshoot this properly. Right now here in CT we have about 8 inches of snow and it is 25 degrees outside. I would pull her into the garage, but my Porsche is "sleeping" in there for the winter.
Any ideas that would make my troubleshooting go quicker, would be appreciated. My wife refuses to drive the car. BTW, the car starts fine.