I had the A/C Compressor replaced on my 88GT but I have a question. What will happen if the High pressure switch and the low pressure switch on the compressor are reversed as to the location on the compressor?l
Currently the A/C runs cold and there are no leaks.
Please respond as quickly as possible as I'm picking up the car this afternoon from the A/C shop. The shop owner told me he put the new switches in the new compressor in the same locations as the one he took out but he feels the swithcs are reversed based on the color coding (Red?White)
I believe the two switches are connected internally on the compressor and therefore it doesn't matter which one goes where. They both operate on the high pressure side of the system.
The low pressure cut-off switch is normally open. This can be tested by using a multimeter set to continuity mode. There should be no continuity between the large round metal body, and the contact on top of the switch. When pressures inside the compressor reach a certain point, the switch will close, and turn on the radiator fan. This is designed to increase airflow over the condenser, and lower the system pressure. The switch closes at approximately 280 psi.
The high-pressure cut-off switch is normally closed. This can be tested by using a multimeter set to continuity mode. There should be continuity between the large round metal body, and the contact on top of the switch. When pressures inside the compressor reach a certain point, the switch will open, turning off the compressor, disengaging the compressor clutch plate. The switch opens at approximately 425 psi, and closes at approximately 200 psi.
Originally posted by zap: The shop owner told me he put the new switches in the new compressor in the same locations as the one he took out but he feels the swithcs are reversed based on the color coding (Red?White)
Thank 's Zap
Sorry Zap, but unless this is being done on the side by a novice, or for free, that's scary. I'm not an A/C tech and have no formal training in refrigeration but I know diagnosing a simple open/close pressure switch is only an ohm meter and attention to detail away. Maybe I expect too much from professionals these days but I certainly don't think you should be the one researching to find the answer to a problem for someone else that is providing a service on a stock arrangement that you're paying them to perform.
Make sure you do a thorough function check before you pay and run it all the way home and for the next few days.
I had the A/C Compressor replaced on my 88GT but I have a question. What will happen if the High pressure switch and the low pressure switch on the compressor are reversed as to the location on the compressor?l
Currently the A/C runs cold and there are no leaks.
Please respond as quickly as possible as I'm picking up the car this afternoon from the A/C shop. The shop owner told me he put the new switches in the new compressor in the same locations as the one he took out but he feels the swithcs are reversed based on the color coding (Red?White)
Thank 's Zap
Please have your installer pay attention to the new switches and whether he grounded out the high pressure switch. For whatever reason, grounding out this switch will cause your radiator fan to run full time regardless of engine temp or if A/C is turned off. You don't want that. //www.fiero.nl/forum/Forum2/HTML/128461.html
The switches need to be grounded to work properly. If grounding the switches is causing the fan to run all the time, there's something wrong with the wiring, or the fan switch. If the high pressure cut-out switch isn't grounded, the system will never switch on, and won't cool.
For whatever reason, grounding out this switch will cause your radiator fan to run full time regardless of engine temp or if A/C is turned off.
No.
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Originally posted by RWDPLZ:
The switches need to be grounded to work properly. If grounding the switches is causing the fan to run all the time, there's something wrong with the wiring, or the fan switch.
If the fan runs all the time, either you used the wrong switch or it's wired incorrectly. The compressor high-pressure cutoff switch is normally closed; the high-pressure fan switch is normally open.
If the fan runs all the time, either you used the wrong switch or it's wired incorrectly. The compressor high-pressure cutoff switch is normally closed; the high-pressure fan switch is normally open.
I apologize. My switches were wired backwards after all. The fan no longer runs after connecting it to the right switch. Thanks for the confirmation!