Prostar ac

[avalongar]

Hey guys do you have any idea what relay or switch I can add to this setup in order to regulate import source for A/C Compressor (Wire A77) and A/C High Press Transducer feed (Wire A77B)? I was thinking to have such a relay/switch so when I turn ON my aftermarket setup the source for both wires comes from Arduino setup and in case if I ever need to diagnose the system and use dealership I can turn off switch and everything goes back to factory settings and dealer be able to hook up DLB and diagnose if needed, plus i can still have factory setup as a backup if anything goes wrong with Arduino and driver can't figure what's wrong until truck comes back to the yard...