I'm installing a vacuum pump to supply the brake booster with vacuum, it came with a sensor that detects low vacuum that triggers power to the the vac pump. I'm not at all sure if this sensor requires power to make it work or if it simply supplies power to the pump by a switch that is activated by low vac.

Anyone have experience with these kinds of sensors?

Thanks,

Chris

Seems like a normally closed switch that opens under vacuum would be the way to do it.  Have you checked continuity across the pins?

Looks also like it's just asking to be taken apart and examined.  Looks snapped on.

your right, normally closed switch that opens at 14 lbs of vacuum.

Thanks