Has any one ever had this problem or know of this problem. I have a 2000 LS Blazer. The Compressor comes on sometimes and sometimes it wont. Seems to come on after the truck has been sitting for time, over night, from the time I make to work til lunch, and from lunch to time I get off. So for a few hours of sitting it will work, but not the whole drive after it comes on, usually 20 minutes or so then it kicks back off. Any solutions?

 

There could be a problem with the charge level. There are two switches on the A/C system, a high pressure cut-out and a low pressure cut-out. The high pressure cut-out is located on the back of the A/C compressor. The low pressure cut-out is located on the accumulator/filter/dryer canister on the passenger side near the HVAC housing.

You can try to externally power the A/C compressor clutch to see if the system blows cold when running. If it does not, then the problem is likely a low charge. A refill kit from your favorite source of auto parts and/or accessories may cure that problem.

You can also read some of the articles located in the Tech Article (DIY) section on A/C troubleshooting if you really want to get into it.

 

When the compressor is on the system does blow out cold air, just cant figure out why it doesnt come on every time and when it does come why it doesnt stay on.

 

Could be a high pressure situation where the high pressure cutout is turning the system off to protect things. You won't know until you get a set of gauges on it.

 

In order to get a correct reading on gauges does the compressor have to be turning?

 

Yes, proper low and high side readings should be taken with the compressor engaged. You may have to jumper the compressor clutch to engage it.

 

So does it take a couple of hours for the pressure to go back down? Just asking because the compressor kicks on after the truck has been resting for a couple of hours. Also I had the intake gaskets replaced dont know if this has anything to do with it, but I know now after the truck rest for a couple of hours there is also a really hard startup. Just checking before I take it back in. Thanks

 

The pressure increases/decreases as the temperature increases/decreases. So yes, it makes sense that it would work for a bit after the truck has cooled off. Sounds like a high pressure cut-out switch problem, but you really should get some gauges on it.

 

Had an intermittant problem that I shared with a guy who had the same thing happening. Just for grins remove the plug from the low pressure switch at the accumulator and look at the connector pretty hard. On mine the receptacle where the pins go in seemed to be a little loose. I took a dental pick and pushed them a little tighter. Worked for me and another frustrated individual. I had chased that problem around for a week before I looked at the connections. Drove me nuts. Hey, you never know.

 

Thanks will try that also this evening. Yeah you never know.