This is probably a real dumb question but where in the engine compartment can one get power from the ignition side. In other words there is no power until the ignition switch is turned to the on position. TIA Pete

If what you want to do is operate a relay you can get IGN power from the yellow wire at the wiper motor. I wouldn’t add anything more than one or two relays to that circuit.

Elree what I want to do is power a supplemental vacuum pump. It has three wires +(Bat), -(Ground) and another +(ignition). I'm wanting to pick up ignition sided power as close to the pump as possible to avoid running a line all the way back to the fuse box. I know you are tired of all the questions but using a relay where do I connect the ignition power wire to, which terminal? And of course the rest of the wires. Thanks Pete

Pete,

There are two circuits up front that are definitely ignition hot:
A) the ignition supply which may be a resistance wire
B) the alternator exciter supply which may also have resistance up stream.

With your internal relay pump I would shoot for the ignition supply and tap into it at the firewall bulkhead.

The wiper motor supply may be ignition hot... but it may also be accessory hot. Would have to check a wiring diagram and verify.

Steve

You could just run a wire from he fusebox. If this wire is just being used for the switched side of relays, each relay will only be pulling less than a 1/4 of a amp, one wire can do a bunch of relays.

"The wiper motor supply may be ignition hot... but it may also be accessory hot. Would have to check a wiring diagram and verify."

Yes the wiper motor is on the ACC circuit not the IGN circuit. Forgot about that because I never use the ACC position.

Depending on what engine/trans the car came with it may have an idle stop solenoid or the wire for one if the solenoid has been removed. It will be a pink 20 ga wire.

Came and is a 350 CI motor and TH350 trans with A/C. I'll try and find the "pink" wire you speak of. Thanks Pete