Vintage Air voltage drop

[sstock]

Originally Posted by jchav62

It's actually the heater/ac fan. It was doing it with just the heater, before I even put Freon in the system. Now that the system is charged and the compressor is cycling on and off, it doesn't drop the voltage.

I'll upgrade the alternator. thanks!

Before you buy another alternator, run a 12 guage jumper wire directly from the battery to the fan lead and check for voltage drop there. The fact that you still have the original fan motor feed wire sends alarm bells to me, just not big enough to carry the load. You know ohms law higher the resistance the more the voltage drop. Quick analogy, the wire from the fuse panel to the fan motor is like you are trying to pass a four lane road full of cars down a two lane street.