negitive switched relay

The following was provided by a vaccum pump mfg:

#30 (-) vichicle ground battery, #86(+) vaccum switch, 87 (-) to (-) of motor(-), #85 ( +) 12Vfused& (+) of motor.

Current set up allows motor to turn on when key is in the run position and senses when vaccum is needed. I would like to have it so that it is power up by key but controled by a negitive ground switch. The (-)ground switch also controls a light in the dash to show it is on.

If I understand your directions this should be your diagram. It already takes a negitive to power the relay on Pin 86. If you put a ground on this pin the motor will come on.

This should be your new Diagram with a Light and a Cut-off switch.

If you want to bypass the vacuum switch just put the wire that should go to the vacuum switch to ground. If you want both just hook the wire to ground and the vacuum switch to the other side of the switch nearest the relay on pin 86.

This would be with the vacuum switch and a Vacuum bypass switch and a light.