Quote Originally Posted by Dorsey View Post
Thanks for this information. My apologies - Yes, the distributor uses contact points. This is the first I've read that my voltage reading is normal for a points ignition system. I still don't get how that factors into voltage drop, but my goal is to get the engine running well again.

By the way, I went to my local Advance Auto Parts today to obtain a new points/condenser set and the young guy behind the counter had no idea what I was talking about. Wow. He was very helpful and took the time needed to help me, but it made me feel even older than I am.
Glad you were able to find parts! The easiest way for me to explain the points system is that it is really a controlled short circuit! That's why the lowered voltage. The points control the flow of electricity through the coil and to the condensor. The condensor "bleeds" off the electricity to ground. The ballast resistor controls how much voltage gets into the circuit. To much voltage the resistor gets hotter and chokes the voltage down, I've seen volts as low as 4 / 4.5 and rarely over 6.. That's why I asked you to bypass everything and go from the battery positive side to the coil positive side - in essence replace the ignition circuit - in a short test run, if it got better then we isolated the circuit was an issue. When the car makers went to 12 volt systems, the resistor became even more important, chryslers were notorius for no starts because of resistor failure, once it happened we would sell a second unit to them to keep in the glove box. I'd even train them how to change them and then swing in to put a new one back in the glove box! One last analogy to understand points theory. Similar to water flowing through a hose. The water won't flow at all if the hose end isn't open, the valve needs to be open / closed for control, This is the job of the condensor, if the condensor fails open no electricity can flow and fill the circuit ( coil) so no worky! If the condensor fails closed it's a direct short and the resistor will be the only limiting control, it usually becomes overloaded and hot causing a failure of the circuit. Back to water flow, this is the same reason for the cooling system bypass near the water pump. If there was no flow at all, the water would boil at the joint between the heads and block, the thermostat wouldn't "see" the overheated water because it can't flow.. The points ignition is similar, the electricity needs to flow so the coil can recharge ... I hope that helps (somehow) I hope it wasn't just me rambling. LOL.. I tried to simplify and offer enough info so you can make an informed diagnoses. It's always harder to diagnose (for me) using words / expressions / phrases.. Good Luck and let us know how it works out!