RPM switch for AC

[69 GTX]

I'm looking for advice on a RPM activated switch to shut off the AC at say 4000 rpm. Something simple & small. Thanks

 

[PurpleBeeper]

What about a nitrous "window switch"? You might have to wire it through a relay since I'm pretty sure the A/C draws a lot of amps.

 

[67 coronet]

What about a nitrous "window switch"? You might have to wire it through a relay since I'm pretty sure the A/C draws a lot of amps.

first thing that came to my mind as well.relay would be a must.