3800SC AC (Page 1/1)
AndrewTHG MAR 31, 10:21 PM
Hey All! Been a minute since I’ve posted but with it warming up down here in Atlanta, I figure it may be time to finally get my AC working. A little background for context: the engine is a 3800SC S3, and I do have custom lines made with the port on the high side of the hose, as well as the provision in my wiring harness to plug into the compressor. I also have researched the parts list, which I used to compile my list below (link here: http://www.fiero.nl/forum/F...2/HTML/128562.html). However, I think this list was used based on keeping the Fiero original engine/compressor. I have a few questions under each part though as to location, if the part works with the 3800, etc. Any help is appreciated! I’d at least like to do the install work on all hoses, o-rings, accumulator, etc. and let a shop flush and pull the vacuum. I’ve never done AC work before, but then again, I’d never swapped an engine before and that worked out fairly well. Just want to learn what I can.
So here are the O-rings needed (or perhaps not…)
• Suction & Discharge O-rings (2 total)
o 4 Seasons PN: 24619
o Are these the O-rings located directly on the compressor body itself? If so, I assume these are not applicable. Are there ones for the 3800 compressor?
• Compressor Hose (Discharge end)
o 4 Seasons PN: 24608
o Is this one that goes back into the body hard lines?
• Compressor Hose (Suction end)
o 4 Seasons PN: 24612
o Is this one that goes back into the body hard lines?
• Under Car line to Condenser
o 4 Seasons PN: 24131
o Should remain the same.
• Condenser Inlet
o 4 Seasons PN: 24131
o Should remain the same.
• Condenser Outlet
o 4 Seasons PN: 24626
o Should remain the same.
• Condenser to Orifice Tube
o 4 Seasons PN: 24131
o Should remain the same.
• Orifice Tube to Evaporator
o 4 Seasons PN: 24131
o Should remain the same.
• Evaporator to Accumulator
o 4 Seasons PN: 24612
o Should remain the same.
• Accumulator to Under Car Line
o 4 Seasons PN: 24612
o Should remain the same.
• Compressor switch O-rings (x2)
o 4 Seasons PN: 24623
o Not needed because of 3800 compressor.
• AC Clutch Cycling Switch O-Ring
o 4 Seasons PN 24606
o This is for the switch that plugs into the accumulator, correct? Is this still needed?

And then along with the O-Rings are the additional parts:
• Accumulator
o PN: T33181
• Orifice Tube
o PN: 38623
• High Side Pressure Sensor
o PN: 13587697
o This is the one that goes into the custom lines on the high side I believe.
• High Side Pressure Sensor O-ring
o PN: 19188397
o Should fit for the above sensor
• Low Side Accumulator Adapter
o PN: 59976
• High Side Accumulator Adapter
o PN: 59978
o This will make it so the AC clutch cycling switch can no longer be plugged in, correct? But then what do I do with that switch?
• 525 Mineral oil
o Do I need this, or PAG oil?

Wow. Lots of info, lot’s more questions! Any help is appreciated, I am slowly piecing all my thoughts together but the more I researched, the more questions I had.
Thanks,
Andrew
olejoedad APR 01, 07:11 AM
When using the three wire pressure switch, you will need to bypass the pressure cycling switch at the dessicator in the front compartment.

Cut the blue and light green wire from the plug, connect the two wires and insulate them.

The PCM and the three wire pressure switch will control the compressor cycling and provide overpressure safety cutout.
darbysan APR 01, 10:33 AM
Do not use mineral oil. Try and flush as much of the existing mineral oil out of the system as possible, as it is not compatible with R134a. Best to use Ester Oil, as it is compatible with R134a, and is also compatible with any residual mineral oil. If everything in your system is new or flushed, then you can use PAG oil. Hard to properly flush the condenser, so unless replaced, Ester may be better choice.

Don't know about all the part numbers you listed, but assume you've done your research. Don't understand Accumulator adapters- a stock ( replacement) accumulator should fit without any adapters.

------------------
'87 GT , '00 3800 Series II SC, 4t65e, Vue Power Steering. (SOLD)

[This message has been edited by darbysan (edited 04-01-2021).]

AndrewTHG APR 01, 01:03 PM
Joe - thanks for the info as always! I hope all is well. My harness is still working wonderfully!

Darbysan - the accumulator adapters change the a header fittings that are used for R12 over to the R134 type fitting. At least I am led to believe this is necessary. And I appreciate the comment on the Easter oil. Oops, I mean Ester! I will keep that in mind!