okay its winter now but last summer i tried to use my ac and it will work sometimes and then most times it didnt work. it would just blow hot air. this is a must in my car to have. so i turned it on and pop the hood. the compressor did not engage with the belt. i dont think its the ac compressor though. is anyone else having this problem or is there someone who knows with experience about this? it be greatly appreciated.

 

Is the system charged? If there's too low/high of a pressure in the system, the compressor won't cycle (safety feature).

 

how do i know if its charged or not?

 

Some cheap gauges from an auto parts store will let you know, basically. If it doesn't have any refigeramt in the system, it's best that you should take it to a shop to have it fully evac'ed and recharged with dye to see where it's leaking from (assuming it has a large leak, it's 'normal' to leak a small amount over time).

I wouldn't recommend doing it yourself with cans, judging by system pressure isn't very accurate at all.

 

how much would they charge to fill?

 

Individual shop prices can vary widely. Call around, look on shop's websites (if they have one), etc.

 

A/C probs have to be addressed 100% there are no short cuts. First you have to do a gauge reading. If your Low side is above 45ish and your Hi side is below 200 + ish then you have a prob. That prob is solved from starting from Point A. Bring down the system. run a vacuum test, if you lose Vac, replace all o-rings. Run Vac again, if it holds then your cool. Open system, flush, replace accumulator, vacuum and charge. If it loses Vac after O-rings are replaces CORRECTLY, your Compressor mite be leaking. Replace it. If you Charge and get screwy readings (low side hi and Hi side Hi) your Expansion valve is trashed ---replace.

Its a damn can of worms ---I tend to just bite the bullet and unless I have a compressor that is obviously oily (leaking) I open, replace accumulator (always a good thing) the Expansion valve (contaminated) Flush, Vac and Charge

 

AKA 'the methodical, shotgun approach'. Unless some of the components are hard to get at (usually, the defective ones), it's a good approach.

 

In the Z , the accumulator is easy, the comp is a little bit of a pain, unless your turboed ---then a big pain. And the expansion valve is always a pain

And actually judging by system pressure is very accurate is you take into account ambient

 

thanks for the info fazzy. and everyone else.