I have a 01 Jeep and the AC is not blowing cold air. When I went to get my oil changed they did a check over and said that it is in working order just lacks any freon to get it cold. So I went to get a bottle to do it myself. Doing what it said to do on the bottle I got nothing. The meter says that there is pressure in the system, but no cold air coming out. I looked into some things on line and it said that when there is no pressure the clutch on the compressor will not engage to keep the system from breaking. I noticed that it would engage and then stop after a second, but still will not full engage or blow cold air. A couple of sites and videos I watched said that I can give power to it by bypassing the fuse. Is this something that I should try so that the system will circulate the new freon?
If the compressor doesn’t operate the AC system can’t be recharged.
You have to locate the low pressure switch for the AC system, unplug the electrical connector and insert a jumper wire in the connector to keep the compressor operating.
+1 for @Tester and please keep in mind that simply adding refrigerant may not fix the problem. The AC system may have to have a leak of some sort repaired, vacuumed down and new refrigerant added. This should only be done by a good independent AC shop if it’s needed.
Quoting @tester “You have to locate the low pressure switch for the AC system, unplug the electrical connector and insert a jumper wire in the connector to keep the compressor operating.”
and THEN you may be able to put a complete charge into the system. That doesn’t necessarily mean a charge will fix it. It probably has a leak somewhere. Unfortunately JGCs seem to often have leaky evaporators. That requires removing the dash to replace the part. If you don’t easily find a leak elsewhere, suspect the evaporator.
It takes a certain amount of pressure in the system to close the pressure switch and engage the compressor. It takes about 3 cans of Freon to fill an empty system…The one can you put in may not have been enough to raise the pressure to the point the compressor kicks in and stays kicked in…You could try adding a second can, but that begs the question of why does it need Freon? If it’s leaking (it must be) then you are wasting your money until the leak is found and repaired…In your effort to install one can, how much do you think you got in? Even though the compressor is not running, most of the Freon will go in if you hold the can bottom side up…ALWAYS wear safety goggles…One drop or Freon in your eye and you are blind…
You never/ever introduce refrigerant as liquid on the low side. If the compressor kicks on when doing this, it’s bye-bye compressor.
In the business it’s called slugging the compressor.