[zippy79]

I was hoping to get some suggestions on where to start. I have a 79 spider that works most of the time. Last fall I was gettinf ready for Wheels of Italy and it began. When I turned the key there was nothing, no lights no clicks, just dead. Voltage at the battery was about 12 v. No votage at the alternator, I believe I had voltage at the starter. I have cleaned the grounds and connetctions, pulled the starter and it tested fine. The no power situation happens randomly, sometimes when I am checking voltage at different points power comes on, now it gets wierd. If I had the no power situation and the power kicks in, when I turn the headlights on power goes dead. Since voltage is only around 12 V at battery when the car is running I was told I could have corroded cables, so I am replacing them . I was told it could be the ignition, but even if the ignition is bad, when the car is off shouldn't i get voltage at the alternator? Also could my problem be the voltage regulator?

 

[Andrew]

Sounds like your ignition switch is working intermittently. The electrical part of it comes off the with a circlip, and you can see how the contacts and springs are. Disconnect the battery and mark the wires before removal. You have to remove the bottom "clamshell" of the steering column cover to get at it.
Other things (lights, horn) wires not through the ignition switch should work fine regardless of how the ignition switch. The regulator should not come into it when the car is not running.
Andrew