A/C not working on cold start
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TECH Enthusiast
Joined: May 2008
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A/C not working on cold start It's about 100F here and A/C system is acting up. On a cold start, the fan came on and A/C compressor would not start. Drive a few miles, turn the engine off, restart and it blows cold air like normal. Does not appear to be under or overcharged - just won't always start.
Any ideas? I have a set of A/C guages - anyone know what hi and low side pressures would be considered normal?
Any ideas? I have a set of A/C guages - anyone know what hi and low side pressures would be considered normal?
The A/C compressor is LS1 cars is driven by the main serpentine, but a magnetic clutch allows it to be engaged and disengaged as necessary. Sometimes that clutch fails -- I had to have mine adjusted by the dealership because the two plates were scraping when the A/C was disengaged. It isn't too expensive to have done; I think you need special tools to do it. Another mechanic had originally suggested replacing the entire clutch assembly, but adjusting it is way cheaper than that.
If you peer around the intake baffle (if you still have a baffle -- aftermarket intake lids don't) you should be able to see the A/C unit on the leftish side of the engine bay. Have someone turn the A/C on and off and check that the clutch is engaging and disengaging properly.
If you peer around the intake baffle (if you still have a baffle -- aftermarket intake lids don't) you should be able to see the A/C unit on the leftish side of the engine bay. Have someone turn the A/C on and off and check that the clutch is engaging and disengaging properly.
Thread Starter
TECH Enthusiast
Joined: May 2008
Posts: 537
Likes: 1
Thanks for suggestions.
Freon is fine and compressor clutch not an issue. (a/c has its own belt, not on main belt) Looks like it is either a relay or pressure switch nnt functioning right. Tried it this evening and worked like it was new. Intermittent electrical problems are always a bitch.
Freon is fine and compressor clutch not an issue. (a/c has its own belt, not on main belt) Looks like it is either a relay or pressure switch nnt functioning right. Tried it this evening and worked like it was new. Intermittent electrical problems are always a bitch.
