[brad01]

Once my car fires cold its 12.2 volts and as it warms up a couple minutes it will drop to 9.7 factory resistor wire

[gtobird]

Originally Posted by brad01

Once my car fires cold its 12.2 volts and as it warms up a couple minutes it will drop to 9.7 factory resistor wire

Just to clarify.........

I believe the factory wiring for a points type distributor was set up so that when you turn the key to the start position with the starter turning, the voltage to the distributor is fed off the start circuit directly at the full 12 volts. When you let go of the key, and the key is in the "run" position, the starter circuit is then open and voltage is fed off of the "run" position circuit through the resistance wire so it then drops to something less than 12 volts (9.7 volts may very well be correct). My understanding is that a full 12 volts to the points will fry up the points quickly if left running so the auto manufacturers wanted to keep full voltage at the distributor when cranking for a hot spark and then drop it back down right after the engine was running.

In a factory wiring setup for our cars built with points distributors, it's not a matter of whether your car is hot or cold. It just has to do with the position your key is in as to how many volts are fed to the distributor. Admittedly, you could possibly have a modified setup with a temperature sensor (switch) with a resistance circuit to drop the voltage when the engine is warm. I've never seen that done, but there are all sorts of ways to do this stuff if you are electrically inclined.