Using oil sending wire to energize small relay

[OSUChE]

I want to use the green and white oil pressure switch wire to energize one of the small Ford type relays. I'm doing this because I don't want to relay to activate until I have oil pressure.

This relay is to close the circuit on a larger solenoid to charge my second battery once the engine is running.

The engine is out of the car right now so I can't check the voltage/current draw myself. I want to know if anybody can tell me if this would have an adverse effect on the oil pressure gauge?

I plan on placing the relay inline such that when the pressure switch closes the circuit, the current will in turn energize the relay.

Any thoughts?

Thanks!

 

[Flash]

The gauge isn't really a gauge anyway so I'd go out on a limb and say it doesn't really matter.

How's this for an idea - use the standard sender for your charging dodad then install a real oil pressure gauge.

 

[OSUChE]

Kinda what I'm thinking... When the new engine goes in I agree; time for a real oil pressure gauge ;-)