Air conditioner compressor not coming on?

   / Air conditioner compressor not coming on? #1  

hardhat

Silver Member
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Jan 24, 2011
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I noticed this morning that the ac compressor was not on even though the switch and fan were on. It has been unusually cold here in mississippi (47 degrees this morning). Does the compressor have a low temp cutoff? It was working fine yesterday when it was warmer. Just wondering if any of you have experienced this. I will get to test it again this evening.
 
   / Air conditioner compressor not coming on? #2  
That is a good possibility (too cold to run).
Also check the electrical contacts, as a bug can get under/between and keep the contact from closing (happened to me when an asian (lady) beetle crawled in there. When I called the A/C man, he suggested checking that as there had been several problems. Sometimes, the switch had to be changed as the beetle caused arcing and ruined the contacts.
 
   / Air conditioner compressor not coming on? #3  
The compressor will not cycle on if the refrigerant pressure is too low, you may need a re-charge of freon, or whatever it uses. Possibly the pressure switch may be defective.

Sean
 
   / Air conditioner compressor not coming on? #4  
The compressor will not cycle on if the refrigerant pressure is too low, you may need a re-charge of freon, or whatever it uses. Possibly the pressure switch may be defective.

Sean

What he said. You can buy 'non freon' refrigerant canisters at auto supply stores. An advancement in consumerism. We are now allowed to perform maintenance on automobile air conditioning systems. $20 bucks.
The hookup is a no-brainer. It only fits one place.
 
   / Air conditioner compressor not coming on? #5  
Seems there are several possibilities. A bad switch could certainly cause that. And it could be that the system is just undercharged. If it was working well earlier this year and now isn't, I would suspect something other than a leak. That said, if you pick up a can with a gauge attached, and find that there is very low residual pressure, I would advise getting it fixed. If it leaked down that quickly once, it will do it again. Also, if it has emptied completely, it needs to be repaired, and then evacuated prior to recharge to prevent further damage to the compressor.

Dave
 
   / Air conditioner compressor not coming on? #6  
What he said. You can buy 'non freon' refrigerant canisters at auto supply stores. An advancement in consumerism. We are now allowed to perform maintenance on automobile air conditioning systems. $20 bucks.
The hookup is a no-brainer. It only fits one place.

I love those things! Customers bring me their car that they tried to fix by topping off and end up with more things wrong. An overcharged system can perform just as poorly as an undercharged system.

Dave
 
   / Air conditioner compressor not coming on? #7  
I love those things! Customers bring me their car that they tried to fix by topping off and end up with more things wrong. An overcharged system can perform just as poorly as an undercharged system.

Dave

Some years ago, the air-conditioner quit cooling in my '77 Dodge pickup. The sight glass showed nothing moving, so I figured it was low or out of freon. I got my gauges and freon and when I turned the air-conditioner on, the pressure almost pegged the gauge; dryer completely stopped up. That made me decide right then to never use the single hose that some used to add freon. I'd always want the two hoses and gauges.
 
   / Air conditioner compressor not coming on? #8  
What is it your working on? Most automotive systems have an evaporator temp sensor. The purpose of this sensor is to keep the evaporator from iceing up. The a/c system is capable of turning the evaporator housing into a solid block of ice.
Some cars also have an ambient temp sensor to keep the compressor from coming on if the outside temp is too cold. There are also low pressure cut-out switches and engine overheat cut of switches. The compressor is also control by the engine computer on many cars. Lots of possibilities on the cause of the problem.
If your problem is with a car, post year, make and model and I may be able to give you specific info.
 
   / Air conditioner compressor not coming on?
  • Thread Starter
#9  
This is a 2011 toolcat f series. I will try it again this afternoon when it is warmer. I hope it just didn't kick on because it was cold outside.
 
   / Air conditioner compressor not coming on?
  • Thread Starter
#10  
The other piece of information that might help is yesterday morning it did the same thing, but when i turned it off and then back on, the ac worked and blew cold air. Maybe it was just chance. I don't think it is low freon as I have seen cars with low freon cycle rapidly before they would stop completely. Plus the normal operation yesterday after an episode of it not coming on argues against a leak. I am thinking loose connection vs low temp switch. I just didn't know if these things had a low temp switch.
 
 
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