Just traded for an '88 Sunbird, with a 2.0 OHC, 5 speed. The a/c was low of freon. Could not get the compressor clutch to engage unless power was provided to the clutch directly from 12V.(Assumed low freon caused the non-engagement problem). After providing direct 12v. power, and evacuating and recharging the system, I have cold a/c. However, when trying to get the clutch to engage by turning on the dash switch (either max air, or normal air), still no engagement. The cooling fan does come on when the selector switch is either of those two positions. The blower fan operates correctly. The controller changes the air output to the proper positions. Where should I look for the problem? Thanks in advance, David.
Where is the a/c relay located? Does the a/c relay also cause the cooling fan to come on when the interior panel selector is in either of the a/c positions (max a/c, or a/c)? If so, then the relay on my car is ok, as the cooling fan engages when the selector is in either of those positions. I have also been told that the low pressure switch in the a/c system may be bad. Is this switch located on the back of the compressor, or in the high side or low side line? Thanks, David.
I believe in 88 they were still using a fuse-type low pressure switch. It's on the compressor. Easy to test, unplug the clip right next to the pulley on the compressor, check for voltage with the key on and ac set to max. You should get power there. If you don't, check the low pressure switch for continuity.
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John Wilken
2002 Cavalier
2.2 Vin code 4
Auto
Thanks to all for the tips on checking the low pressure switch. I'll be doing that tomorrow. David
