Dashboard electrical issues=won't idle

[tito911s]

Let me just describe the issues I'm having and hopefully someone can help me track down some areas to look into more closely.

Car in question:


1976 Porsche 911s, sitting for a few years. Control plunger was stuck, and after fixing the car ran. There was a drain in the system so the regulator, alternator, and battery were replaced. The car ran for a little while and then lost power and now is dead. There was an Ungo alarm box in the car, and it was properly removed. It will crank with a fresh charge, and as soon as the starter disengages it dies. I'll list the electrical problems that pop up as well (note that all fuses are ok):

1. the spedometer jumps to 30 mph when you turn on/off the lights or adjust the dash light brightness (this is an electric spedometer, not mechanical)

2. the generator dummy light now does not come on, although it did before the regulator was replaced

3. the fuel pump is louder than it was before

Clearly, there is a short or drain, or crossed wire, somewhere that is affecting not only the dash but the power going to the ignigion system. Short of redoing the entire harness, I was hoping to narrow it down to an area to focus on. Any ideas are greatly appreciated.