I had a shop fix my a/c a few months ago. They tested it and said it needed a new compressor and dryer. I've used it maybe 15 times since I got it back; it's not a daily driver. Yesterday i drove it a few miles and I stopped at a gas station, when I pulled up to the pump I had white smoke coming out of the upper vent by the driver window. It was more like humidity/moisture. I'm pretty sure the a/c was off , but i do remember turning the a/c button up to make sure the compressor kicked on. I went to drive it today and no a/c. The compressor is not kicking on, and i checked the fuse and tried a new relay. I am thinking all my refridgerant leaked out. How do i proceed? Can i test this myself? I've never dealt with a/c systems before. thanks.

 

I would proceed by heading right back to the shop that worked on it. I assume that a new compressor, drier, etc. was not cheap.

 

I plan on doing that, but i want to test it before i bring it back, and not tell them i tested it.

 

If you are smart you wouldn't mess with it. Because if they see anything and I do mean anything out of place you will void any warranty and you will be billed for anything that they will have to fix. Play it safe and let them fix it if you still have a warranty left on the work they did.

 

good point

 

this isn't exactly a recommended practice but a quick test would be to pull of the low side valve cap and use a pen to compress the valve in there to see if any refrigerant comes out. it is the same kinda of valve as a tire valve. should have good pressure coming out of it. if nothing comes out then you have a large system leak. if the system doesn't see pressure in the ac line it will not run the compressor. hopefully it's related to repair work and the warranty will cover repairs but i suspect another line has leaked out. hopefully only a line and not an evaporator.

 

Sounds like you've got a leak somewhere or they put in compressor with a defective pressure switch (it happens). Take it back and have them make it right.

 

thanks for all the advice. I'm going to bring it back to the shop this week. I'll post when i know what is wrong. I hope it's not the evaporator core.

 

does anyone know what a fair price is for a shop to do a dye test to check for leaks? I'm thinking they are going to charge me if it is something other than what they previously did.

 

No idea, I do them myself. You can get the dye and a UV flashlight pretty cheaply

 

Any where you go there goin to charge about 100 bucks or more just because they have to hook everything up as if they were goin to charge to a/c. If there is still vacuum in the system then you can do it yourself. If you do not have vacuum, you'll have to have it vacuumed down in order to apply the dye, if its a big enough leak the dye won't help you'll have to maunally check every hose and fitting.

 

thanks

 

I just got back from the shop. They tested it and it had nothing left in the system. So then they did a vacuum test and it passed with no leaks. They filled it up with dye and it didn't show anything. they have to get a sniffer, so I have to bring it back to them.

 

I drove it around for a few hours today after I got back from the shop, and obviously after my last post. I can see dye coming out of a hose on the bottom of the firewall, passenger side, under the dryer. I am assuming the evaporator is behind that section of the firewall.
I just think the shop misdiagnosed the compressor and dryer. That it was the evaporator the whole time. The mechanic even told me today that the other guys at the shop don't know how to use the machine and that he did not work on my Jeep the last time