Fiero ac compressor switches (Page 1/1) sdgdf JUL 31, 07:17 PM My 3800 88 coupe ac project continues. The car has a duke V5 ac compressor. I have the car all wired up for a 3800sc compressor, which also seems to be a V5, a later version of it? I have the high pressure sensor in the line, and it’s easiest for me to just use a fiero v5 (otherwise I gotta get new end on my line). I was told to wire the ac request through the low pressure switch on the back of this compressor. IIRC I did research and found threads that say the original switches aren’t made and the new ones for the back of the compressor are different? Which one is which and where do I buy them? RWDPLZ JUL 31, 09:00 PM We had a thread for this, but the image server got nuked. With 3800 swaps, typically the AC is controlled through the 3 pin switch from the original engine, mounted to a port on a custom hose set. The original 3800 compressor doesn't have switches. https://www.fiero.nl/forum/...079990.html#lastpost For the original V5 Fiero compressor, the original parts are as follows: V5 wiring diagram (use L4 branches) sdgdf AUG 01, 05:20 PM quote Originally posted by RWDPLZ: We had a thread for this, but the image server got nuked. With 3800 swaps, typically the AC is controlled through the 3 pin switch from the original engine, mounted to a port on a custom hose set. The original 3800 compressor doesn't have switches. https://www.fiero.nl/forum/...079990.html#lastpost For the original V5 Fiero compressor, the original parts are as follows: V5 wiring diagram (use L4 branches) Ty, what if I don't use the switches on the back of the Fiero compressor? Just the 3-wire switch I have on the line? It allows for the compressor to be turned off if the pressure is too high, as detected by the PCM? It was recommended I use the low pressure switch too. For what, to allow the system to be cut off if the pressure is too low? RWDPLZ AUG 01, 09:15 PM quote Originally posted by sdgdf: Ty, what if I don't use the switches on the back of the Fiero compressor? Just the 3-wire switch I have on the line? It allows for the compressor to be turned off if the pressure is too high, as detected by the PCM? It was recommended I use the low pressure switch too. For what, to allow the system to be cut off if the pressure is too low? I believe the 3-way switch has that safety functionality, but I'm not familiar with the way the 3800 system works. Anyone that has done a 3800 AC system, feel free to chime in.