Hello everyone,
My AC isn't working. I checked the 7.5 amp fuse and also tried to jump the relay as well as the pressure sensor with no luck. There's power coming to the pin 1 on the relay when I jump it there's no spark while connecting to pin 2. Both radiator and condenser fans turn on but the compressor. I also checked the current and my test pen lights up at the one pin connector going to the compressor. Please help. Thanks!

 

There is a safety switch that will turn off the compressor if the pressure is too high or too low, check your system pressures.

 

^^^^ I was going to suggest the same thing as I'm guessing pressure is low.

 

Chances are the pressure is low due to high and low side Schrader valves leaking. How do I charge the system if it's not engaging the compressor?

 

Step 1) (obviously) replace the leaking Schrader valves

Step 2) The low pressure is preventing the compressor from kicking on. As you're filling the system (with an external can and a proper set of manifold gages) the compressor should automatically engage once the low pressure switch setting has been met.

 

Those pressure switches can go bad. Happened to me before. Or the can of refrigerant is freezing up. Sometimes shaking it or turning it upside down helps. Eventually there should be enough pressure that the switch will let the compressor turn on. If you get to like 60 psi on the low side, and it's still not kicking on, chances are that switch is bad.

 

Pull a vacuum first if your valves are leaking, chance are you've introduced air into the system so you'll want that (and the associated moisture) out. Replacing the valves is simple enough, and before you add more refrigerant (and while the valves are out), add some UV dye to the low side to aid in future leak detection.

 

Also generally good practice to replace the receiver/dryer when your system has leaked out all refrigerant and taken in outside air and particulates. It's a cylinder full of dessicant that gets saturated, then it can't do its job of removing harmful moisture. Moisture and contaminants lead to a burnt out compressor.

 

I replaced the valves on both low and high port which fixed the leak. I used the diy recharge can and the system took the refrigerant without the compressor engaging. I attached the second can and the system didn't take any refrigerant in and the compressor isn't kicking in either

 

That’s because the proper way to recharge AC is to use a set of manifold gauges and a vacuum to put the system in vacuum, then after it holds it for an hour, then you can recharge. Dont skip and be lazy

 

I went to autozone twice to get the manifold set. First one the low side fitting was defecive. I went back to get another set and that set had the missing rubber seals causing leaks within the fittings. I gave up on autozone after that. I had the vaccum pump rented as well. I will try it again next week and report back. I really hope the compressor kicks in after I recharge with the manifold set.

 

I am not an AC mechanic but if you replaced both schrader valves then you lost all pressure. And if you tried to charge it without the engine running, my GUESS is that you filled or pressurized the low side while the high side remained low or empty. So ya, the compressor will not kick on in that case.. I think the engine needs to be running but I do not know for sure the procedure.. There are many videos on youtube. Some better than others. But I do know that as thoiboi said, you need to put a vaccum on it to get out all the air.. (assuming you pulled the scrader valves out) It takes like 20 or 30 minutes to evac and vacuum it down. Yes my scrader valves were leaking this summer and they were replaced.
But I had a shop do it who has an automatic evac and refill machine. (Expensive!)
By the way, if you put a vacuum on the system, the new R134a cans should go in faster.. And you should be able to fit more R134a in it. There is a AC maintenance Label under the hood that tells how much the entire system holds
Good luck!