electric vacuum pump

[71chargerrtclone]

I wasn't sure where to run a positive wire for my 12vdc vacuum pump (power pump when car is on). Needs to only run when the car is on.

[A383Wing]

I would run a relay between power source and pump....tap off the ballast resistor when key is on to power up relay. Have wire from battery to relay, then to pump.

numbers on relay would be as follows:

30 to battery
87 to pump
85 to key on source
86 to ground

This would be a standard 4 or 5 pin Bosch relay found anywhere...don't forget the fuse in the power wire from battery to relay for the pump