The switch in the OEM compressor was a single wire that grounded out with high pressure which throws the recirc door closed-- puts the system into recirc when head pressure goes above 275psi-- so is yours a single wire switch? if so ground it permanently-- there was a TSB to do this on '88 and 89s --I did a bunch of them,......
you could also transfer the coil from the new compressor to the old compressor--I would have just put a new coili on it, instead of buying a whole compressor
'95 Chevy 3500 454 Dually 142,000 miles
'94 Chevy Astro Van 358,000 miles!
'86 Buick Park Ave 192,000 miles
'86 GMC S-15 Pick-up 150,000 miles
'92 Chevy Lumina Van - 265,000 miles- given to me to see how far it can go! all above are white!