Good power source for 30 amps?

[BlackSpeed66]

I'm working on wiring up the air pump assembly for the power lumbar support from an e38. The factory wiring diagram for this car has the pump and associated wiring coming from a 30 amp power source. Is there any way I can test to confirm a maximum current draw on the pump to see if I can tap into an existing power source that uses less current? I find it hard to believe that the pump alone would need 30 amps to operate; but then the e38 likely has many other accessories being powered on that same circuit.

Thanks for the help!

[StereoInstaller1]

If you wanted a switched 30A source, I am gonna suggest you use a relay and make your own.

Get your main power from that junction point under the hood.

[BlackSpeed66]

Thanks Luke. After perusing through more wiring diagrams on my lunch hour, the e30 power windows & sunroof also run from a 30A circuit. I think I would be safe tapping into this from the window breaker switch in the HVAC panel. Wiring the air pump after the breaker in theory gives me both the fuse and breaker as protection if the pump draws too much current for some reason.

Looking at the e38 wiring diagrams also confirms that all of the power seat functions are powered on the same 30A circuit as well so I think I'm good to go.