I will be installing a DUI HEI-style distributor in my ’65 Mustang hardtop with an inline-six. This unit requires direct 12V power from the ignition switch. I know I would need to connect this 12V ...

Here is a simple mod to allow the speed of any 12V fan to be varied. All we need to do is insert a rheostat or variable resistor in the 12V wire to the fan. The rheostat should be rated at least 3 ...