I have recently been having some electrical issues with my 66 and I thought I should share them. I am an electrician by trade and thoroughly enjoy an electrical challenge. This one nearly had me stumped. Here is my set up. I have the stock style alt with an OEM type external regulator and a Mallory Unilite 9000 distributor. My starter is a couple months old. Here is what happened: I went to start up my truck a few months back and it would fire up but as soon as you let the key go it would die. So I figured that I had a problem from the key to the starter. The key cylinder and switch were original so I figured it is probably that. I replaced those parts and still I had that same problem. To get it running I would put a jumper wire from the alt to the ballast resistor and it seem to do the trick most of the time. Every so often it would still die for no reason. Next the battery would be dead so I started to undo the neg on the battery. When this happened I thought that I now knew what the problem was. So I replaced the voltage regulator with a solid state type (they are lighter in weight and have no moving parts like the OEM type) and no more dead battery but I still had the dyeing issue. I figured it must be in the starter (starter tested good) so I replaced the solenoid and I no longer needed the jumper wire. No it would run but would die about three or four times on my way to work. Now totally baffled I ran across an article on the web about Mallory ignition modules. It totally described my problem with the motor quitting with no warning. http://www.centuryperformance.com/mallory-unilite-and-e-spark-testing-spg-150.html I performed the test and it was defective. I have ordered my new module and a filter to protect it. Now here is how it all went down. The voltage regulator stuck closed acting like a bad diode. This in turn would drain the battery and sent a voltage spike to the ignition module and frying it. If you are using a points eliminator kit, unilite, accel or flame thrower in your distributor watch out for this problem. A bad regulator will fry it.
