86 Bronco r12 upgrade

[Broke_again]

New to the site and searched for answer to no avail.

Upgrading system from r12 to r152 with ester oil. I've placed 2 e-fans in front of condenser. I want to trigger them from the refrigerant on the high side port via a "tee" adapter and trinary? / binary? switch so the fans only come on when needed.

Anyone know of such a switch?

What pressure settings on/off should I be looking for?

Thanks in advance for you guys'/gals' help

[Tim]

Just run a "relay" setup that triggers off the cycling switch.