LannyL81

The compressor that came with my '81 is long gone so I do not have it to compare; am seeing R4 compressors with switch and non switch;..?? Is this a low or high pressure switch that is in the back of the compressor or what??

The wiring diagram in the Service Manual does not show a switch in the compressor just the one that is in the line between compressor and dryer or accumulator.

And since R12 is also long gone....will the original condenser work with R134 or does that need to be replaced along with all the O rings? I have a new dryer / accumulator.


Thanks

chvet73

If you want to get the most out of this system change the condensor to a crossflpw style. Then convert to a Sanden compressor. You will get far colder 134 air that way.

I also recommend a C4 blower motor.

LannyL81

Okay Sanden 508 compressor....any chance these have the same bolt spacing as the original R4 style?

Off to search for a cross flow condenser.....

What is the advantage of a C4 blower motor?...more cfm?...do the blower resistors need to change to do this?
Does a C4 blower motor have the same shaft size so the fan will fit?

Off to search on this more as well.....

mikep3

http://www.classicautoair.com/GM_OEM...ompressor.html

Many of the ac suppliers have systems that can upgrade your R4 to Sanden type compressor. Classic has a basic system with compressor, mounting brackets, hoses and filter. Also there is a under the hood system that includes a new condensor.

manfroni

I purchased a N.O.S. R4 compressor from a supplier on eBay. I also found the old freon there. Changed the dryer and all o rings and it works like new. You don't even feel the compressor go on. Don't forget to replace the squirrel cage with a C4 part.

LannyL81

mike3pP I checked-out classicautoair.com but did not see anything for my '81 Corvette, only up to '76. Would I need to go to the universal kits?

manfroni: you were able to buy R12 off of ebay? I need to check this out!

I have a new R4 compressor sitting in a box that I bought probably 8 yrs ago, still sealed...but there is no switch or electrical connector on the back side of it, only the two pins for the clutch. I have yet to go looking for the electrical connectors for the compressor....and I do not remember if the one I took off had a connector on the back side or not. Still have not determined what this switch or non switch type is yet.

mikep3

First I would get an assembly manual for an 81. That will show the piping, wiring and pressure switches plus the connectors.
Classicair has complete systems for c3 to 76. The under the hood systems have just the pump and hoses. Their website is misleading at times.

LannyL81

mikep3: yep got the assembly manual, just not 100% readable.

Will have to call Classicair and ask some questions.

Slotehog

I have been considering AC in my 80 and have the same problem. Classic auto air recommended the "Street Rod Cooler III". A kit they do not list on their site.

They sent me a PDF for the kit "document #1-1091" which is not on their site either. You can always email/call them to send it to you to see if it will work for you.

Good luck

Andy

Seasoned80

Just received a parallel flow condenser from Classic Auto Air today. Not installed, but looks like it will fit perfectly. Prior upgrades include new barrier hoses and a Sanden style compressor and Allen Grove brackets. Plenty cool on the road, but really drops in traffic. New condenser should be big improvement.