A/C Comp. won't switch on HELP!!!!!!!

So I replaced the compressor in about 30 mintues and skip the vacuum test and flush and go straight to filling freon.. Well I start the car turn the air on and of course it won't engage.. Bnaylor got any clues? Also they gave me some dryer inline filter... It looks alot like the thing by the right front tire but alot smaller.. My question is where does it go along with a metal filter they gave me (looks like a needle).. I just spent 330 and really don't want to take it to a shop...

Skipped the vacuum test and flush? Assuming the install was a success, I hope you did pull a vacuum before filling the system with freon. This removes contaminants that will damage your system over time. Have you used any gauges on the system? The compressor will not come on until the pressure switch determines the system is not running low on freon. Hope this helps.

Skipped the vacuum test and flush? Assuming the install was a success, I hope you did pull a vacuum before filling the system with freon. This removes contaminants that will damage your system over time. Have you used any gauges on the system? The compressor will not come on until the pressure switch determines the system is not running low on freon. Hope this helps.


Well it says to add freon once the compressor is on.. I tried adding the freon with the car off but it doesn't seem to go in... I've got two gauges, for the low side and high side... I'll probably just replace a couple things and take it to a shop and have them pull a vacuum and make sure there's no leaks...

Well it says to add freon once the compressor is on.. I tried adding the freon with the car off but it doesn't seem to go in... I've got two gauges, for the low side and high side... I'll probably just replace a couple things and take it to a shop and have them pull a vacuum and make sure there's no leaks...

Was the compressor the source of your leak or was it just malfunctioning?

Whenever you replace major parts like a compressor the system should be evacuated and then recharged.

Like the other poster stated there is a combined low/high pressure switch and the refrigerant charge must overcome the low pressure threshold before the compresssor will cycle on/off.

Was the compressor the source of your leak or was it just malfunctioning?

Whenever you replace major parts like a compressor the system should be evacuated and then recharged.

Like the other poster stated there is a combined low/high pressure switch and the refrigerant charge must overcome the low pressure threshold before the compresssor will cycle on/off.


I doubt it, I would find it suprising that 3 compressors would be the problem.. I'll get a shop to do the freon and vacuum part but I wanted to replace a couple of things before that... I got this from AZ, Drier filter reciever and a long metal looking filter... Do you know where these part go (location on the car)... Also I have to go back and get the (forgot the name but it's the part that you have to get to have the warranty for the compressor and it's located under the right front tire)...

Well I tried taking out the filter located in the front of the car connected to the radiator or whatever it is.. The book said to get needle nose pliers and pull it out.. Well I tried and tried and ended up tearing it and leaving half of it in there.. I'll take it to get fixed but I'm having trouble locating the Drier filter reciever (that's what it's called on it) I lookied in the book but says nothing about it.. Did AZ give me the wrong part thinking it was (that part located under the right tire well)

Well I tried taking out the filter located in the front of the car connected to the radiator or whatever it is.. The book said to get needle nose pliers and pull it out.. Well I tried and tried and ended up tearing it and leaving half of it in there.. I'll take it to get fixed but I'm having trouble locating the Drier filter reciever (that's what it's called on it) I lookied in the book but says nothing about it.. Did AZ give me the wrong part thinking it was (that part located under the right tire well)

Are you referring to the black square thing right in front of the radiator? That is the condensor. Otherwise what filter?

The receiver dryer is located on the passenger side of the front end. You need to remove the forward splash guard bolted to the front bumper cover to access it. If you follow the compressor lines to the right they will connect to the receiver drier.

Are you referring to the black square thing right in front of the radiator? That is the condensor. Otherwise what filter?

I wish I knew what you were talking about.. I didn't notice any black square in front of the radiator.. The filter is actually located inside of the pipe which you pull out...




The receiver dryer is located on the passenger side of the front end. You need to remove the forward splash guard bolted to the front bumper cover to access it. If you follow the compressor lines to the right they will connect to the receiver drier.


Well if that's the case they gave me the wrong one.. Because this one is about two times smaller and the connections are wrong... That's what I replaced also along with the compressor everytime but this time this is what they gave me... UGH!!!!!!!!!!!!!!!!

I wish I knew what you were talking about.. I didn't notice any black square in front of the radiator.. The filter is actually located inside of the pipe which you pull out...

Well if that's the case they gave me the wrong one.. Because this one is about two times smaller and the connections are wrong... That's what I replaced also along with the compressor everytime but this time this is what they gave me... UGH!!!!!!!!!!!!!!!!

Yeah, depending on your year Alero the parts for AC will be different. The 99 - 01 had one type and the 2002 and up had another. I know the GM part numbers for the receiver drier unit are different for those years.

Can you post pictures here or links to pictures, maybe someone would be more apt to be able to help you.

Can you post pictures here or links to pictures, maybe someone would be more apt to be able to help you.


I'll post the pics Monday afternoon... I'm not going to get it fixed anytime soon as I'm in the process of buying a home and need every penny...