Yet another a/c question
My a/c isn't cooling. Last summer I had it converted to R134a and it worked great. The first time I tried it this spring - nothing. I bought a can of refrigerant and added it, but the system doesn't seem to want to take it all. I'm afraid to keep pushing it in for fear of overcharging. My sight glass is foamy. How long should it take to add a can? Does the foaminess ALWAYS mean it's not full enough, or could it be too full already? If so, why won't it take any more? The can is not anywhere near empty.
I have noticed that my aux. fan isn't coming on - ever. I'm pretty sure this is because the system pressure is low. I've jumpered the pressure switch and the fan came on. I also checked fuses, relays, and the temp. switch for obvious signs of malfunction, but I don't have specs to test them with a volt/ohm-meter.
Other info. - the low pressure hose is not getting cool at all. The compressor is engaging properly now, though it wasn't before I added any refrigerant, indicating that pressure was low enough to trip the cut-off. Occasionally I can feel slight cooling from the dash vents, but it's not much and it doesn't last very long.
So it seems that I just need more refrigerant, yes? But how do I get it in, and how do I know when to stop?