A/C has been blowing no so cold air lately so I thought I might need to recharge it with refrigerant.

I noticed that my low side pressure was very low (almost zero), depressing the needle in the valve didn't even spray. The compressor is definitely engaging and the blower is working.

Does this sound like a frozen expansion valve or are there some other things I should check before diving into this repair.

 

My first guess would be low refrigerant. If your low side is that low, the compressor shouldn't be engaging. What's the high side pressure? I'd have somebody put a gauge set on it before I proceeded.

 

I thought the same thing. I tried to put refrigerant in, but it won't accept it. There is pressure on the low side when the compressor is off, but when the compressor engages there is zero pressure. I can depress the valve and nothing comes out. I bought a nice set of gauges the other day, I will connect with them and report back with high and low side readings

 

No compressor



After compressor kicks on