A/C problem in '00 Blazer

Jul 02, 2009 6 Replies
C

I have a 2000 Blazer that has just developed a problem in the A/C.



The cooling is intermittent. Sometimes the compressor will engage immediately when the truck is started and put out cold air (28 - 32 degree air). Sometimes the compressor will NOT engage for 10 - 20 -



30 minutes and I will get hot air. Then, all of a sudden, I'll get cold air. It might stay cold for 5 minutes or it might stay cold for
30 minutes - and then turn hot again. There seems to be no rhyme or reason - sometimes it works and sometimes it doesn't.


I have charged it with refrigerant (134a with oil) and when it cools, it is REALLY cold.


With the hood up, I can see that the compressor clutch is not engaged when it is blowing hot air and, as soon as the clutch engages, I get cold air.


I don't know much about A/C systems but I'd like to get an idea as to what might be the cause before I commit to spend major bucks on a 10 year old vehicle.


Any suggestions?


TIA


Chuck


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P

You could try the A/C relay. Mebbe it's bad. Wiggle all the wiring, switches....check out the low press switch (think on the accumulator) Good luck.........Pete

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B

Check your high/low pressures. Too much pressure will activate a high pressure switch which will shut off the compressor as will too little pressure.

Basically there is the amount of refrigerant and pressure which should be just right, then pressure switches to monitor this, a relay, and the wiring and connectors.

Not a big deal to troubleshoot and repair if you have the right tools.

The "right tools" are...

-A/C gauge set

-GM factory service manual set:

formatting link

-Multimeter

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A

I don't recall the details but for some Chevy products there was a TSB for this kind of problem and it required replacing some electronic control module. You might want to check with a dealer before throwing too much money at it.

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C

The suspect phrase is, "I have charged it...." If you did it without proper gauges and it is OVERcharged, then the high pressure switch will cut off the compressor after running a short while. Get someone to check the pressure!

Chuck wrote:

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