A/C Compressor High Pressure Switch

Old 06-24-14, 09:47 PM
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A/C Compressor High Pressure Switch

I am replacing the GM OEM compressor on my 1997 Express Van with an after market compressor. The after market compressor did not come with a high pressure switch installed on the unit. What is the purpose of the high pressure switch? How does it work and effect the operation of the compressor? Is it necessary to install a high pressure switch inorder to have a properly functioning compressor? Will the compressor function w/o a high pressure switch installed?
Old 06-24-14, 10:46 PM
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Welcome to the forums.

The high pressure switch is there in case the system is overcharged or the system runs too hot as in sitting there with the engine just idling and keeps the compressor from discharging refrigerant into the air.

Many systems don't have them. It's an extra safety for the compressor. If the new one doesn't have it then that company assumes it's either not needed or that there is a switch in the line.
Old 06-25-14, 08:24 PM
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you need to swap it over or the system will not come on. they didnt include it to save money, and mass produce for a number different cars. with out it the car will think it allways has high pressure. there should be a snap ring holding it in. becarefull not to pry to hard or you will break it.

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