Originally Posted by pizzaguy

Bob, go back to George's post - you MUST have 12 volts at Pin 2 at all times. If you dont have 12 volts there, THAT is your problem. With the car shut off, there will be 12 volts at ALL three pins and when you start the car, pins 1 and 3 will go to zero or close to zero IF the heat controls are at "full cold". At "full hot" they should go very close to 12 volts.

Now, the diagram shows a direct connection from the fuse to the connector at the valves - i'd caution you to take that less than literally. I've found, over the years, that they took a lot of shortcuts in writing the wiring diagram, there may be a connector/splice/etc. somewhere in the path that has corroded, gotten wet, come unplugged, been chewed by a rodent, etc.

But know this: DO NOT waste any time on any thing now, but getting 12 volts to pin 2.