I like to inhibit my Snow Performance system from running unless the engine is turning over. I think this can be done by using one of the alternator tabs as the vacuum switch power source.

It's with a carb.

Anyone done this?

 

I would suggest a power relay would be simplier.....with the trigger wire hooked to something that activates after engine start-up

 

most oil lite sender's ground when there is no pressure, you could use this to operate a relay so the system will only work when there is oil pressure, ( engine is running).