Ok, this gets more weird.
I ran tha AC for a couple of minutes following the gas citcuit and something doesn't add up (or I don't understand how the AC works as well as I thought).
The high pressure line going into the condenser (front, next to radiator) is pretty hot, so far so good. The high pressure line (thinner pipe) going along the driver fender and getting into the evaporator (thru firewall) is cold, maybe colder than ambient. The low pressure line coming out the firewall (thicker pipe with low pressure port) is ambient temperature.
I see refrigerant running on the glass.
Shouldn't all high pressure lines be hot until it gets into the evaporator, and low pressure lines be cold out of the evaporator? Could I have a blockage in the condenser instead of expansion valve?
The high pressure line(s) will be hot (to warm) depending on where you check them and and heat load. For instance if you feel the high pressure line anywhere it comes off of the compressor, over the top of the radiator and into the condenser...it will be HOT, like you can't keep your hand on it hot. If you check it at the sight glass....it should feel warm/hot, but not uncomfortably so. At the sight glass (on your vehicle) it splits off into two high side lines that trace the drivers side fender skirt and along the firewall. Anywhere along that course the line will just be warm.
The larger low side line coming out of the evaporator should feel cool to cold (depending on how long it has run and the heat load).
You need to let the system run a good 15-20 minutes to stabilize and allow some cooling of the interior. I would place the unit on recirculate, temp on COLD and fan on HIGH.
Then check your lines after it has run for awhile. We are just trying to get an idea where the blockage/restriction is.
Yes, it could be at the condenser. It could be at the drier. More commonly it will be the TXV at the Evaporator. IF the low side line coming out of the evaporator never gets cool and the pressure continues to be low or pull into vacuum then its a good bet the TXV or Evap is your trouble.
Just briefly....your A/C works by REMOVING hot air (and moisture) from the cabin. You are NOT bringing cool air IN, you are taking hot air OUT.
The absence of heat is of course what we define as 'cool'. The heat in the cabin is absorbed into the Evaporator and the Cold, Gaseous refrigerant. (Heat can only flow to a cooler source). The gas (and heat) then goes to the compressor, where it is compressed (raises pressure and temperature). It then flows as a hot gas to the Condenser where the heat (most of it) is released into the cooler outside air and the hot gas condenses into a liquid.
The liquid refrigerant goes through the drier (which actually stores some of it until needed), then it travels (still as a liquid) through the small line to the TXV (Thermal Expansion Valve) which meters how much of the liquid gets released into the Evaporator. When the liquid refrigerant (in reality not completely liquid at this point) is released into the Evaporator.....it is low pressure and turns back into a gas which is much cooler. The whole cycle starts again. The Evaporator absorbs more heat from the cabin.
Eventually you have enough heat exchanges that air in the cabin is feeling cooler AND the evaporator itself gets cold... so the air being blown across it aids in the cooling process. BUT the principle of Air Conditioning remains the same: You are removing heat, not bringing 'cold' inside.
