86 air conditioning question

[Bruce Huey]

I sure would appreciate someone's answer to this question. The original compressor on my 200,000 mile 86 finally called it quits. Took it in to a reliable mechanic for replacement and conversion to new freon 134?...After installation, mechanic could not get pressure back to specs...330 or so....always pushing limits of upper 400's He can get correct pressure readings when the cooling fan is activated. However, the fan will not run when the air conditioner is turned on unless he hot wires the relay. He did change the relay realizing that this probably wasn't the cure. He stated that the cooling fan should energize when the air conditioner is turned on. I can never remember the cooling fan running before when I used the conditioner. Does anyone know whether the cooling fan should be activated with the conditioner? Willl the 400 plus pressure in the system cause a problem? I've checked shop manual and couldn't find an answer. Any help would be appreciated.

Thanks, Bruce

 

[Mac]

Bruce, I think you'll get better results in the C4 technical forums so I'm gonna move it over there!! Can one of you C4 specialists help out our friend here? Thanks!!

-Mac

 

[jmccloud]

Cooling fans

Bruce,
My '95 cooling fans come on 'slow' as soon as the A/C is turned on. Once the A/C pressure(???how much) or engine temp (237F) is achieved, the fans turn on high. So if the A/C is on, the fans are on.
Could be a bad 'head' unit in your dash or a bad computer control (ecm).
There are lots of threads on hard wiring the fans. Do a search on the tab near the top of the screen. The A/C will actually work better above 50mph with the fans turned off and your ecm computer should do that as well as turn the fans on as soon as the A/C is turned on.
Hope this helps

 

[bradfordsvettes]

could possibly over charged should be aprox 15 to 20 % less freon when using 134a only my 2 cents steve what is the low side at?

 

[Bruce Huey]

Thanks to Mac, jmccloud and Bradford's for your tips on possible solutions. I'll check on the hard wiring after I get a read on the over-charge level. Do appreciate your help and will post a solution when found. Bruce

 

[Bruce Huey]

With my air conditioning problem on my 86 dealing with high freon pressure and no initial cooling fan with activated auto switch. A new relay and fuse cured the fan's operation on startup. As I found out, the initial start of the cooling fan is necessary to keep freon pressures from spiking. There should, indeed, be intital fan activation when the compressor is engaged just as jmccloud pointed out earlier and with highway speed the fan disengaged. The freon levels with the new 134 were exactly 15% less than the original 12? as bradsford'svettes told me earlier.
Thanks, again, for your advice. Both of your suggestions were right on.

Bruce