I have the 305 TPI where the AC compressor is on the passenger side, if that makes any difference...

My AC doesn't work (I know, nearly everyone has that problem, but I don't think it's due to a refigerant charge. It has never been converted.

With the engine running the belt on the AC spins freely. I was told that when you put defroster or the AC on, the compressor should kick in... it doesn't do anything differently than when the AC is off...

That's why I am stuck. I have no blown fuses, the rest of my heater controls work fine; am I missing something here?

 

it has a low pressure switch that wont allow the compresser to kick on if the freon level is too low. put a set of guages on it and see or push the valve stem in on the accumulator to see if there is freon in it at all. if not, when you charge it up you will hear the low pressure swith kick out and the compresser will then be able to kick in.

 

So if I push the tire-valve looking thing, there won't be tons of pressure behind it? I thought of that but was kind of affraid!

If the low pressure is the case, then it would probably just need a charge, right? Well, a conversion that is, R-12 is about $600 for a can around here...!

 

i use freeze 12, the non flammable kind. been working just fine for me

 

bubbz89 is right, there is a low pressure switch. Another easier way to check if the switch is working or is not activatiting is if you have a test light, or a 12 volt light you can ground ( make sure the light works by touching the positive side of the light to positive on the battery when grounded), then probe both sides of the switch. Make sure your a/c is in th on position. If you get nothing on both sides, you have a wiring problem somewhere before the switch, so the a/c system isnt getting power. Could be the trigger switch on the back of the HVAC controls. If you have power on one side and not the other, you have no/ little freon in your system and need to charge it. If you stay with r-12, make sure to check for leaks! If I were you, Ide try to stay with r-12, because it works the best. But since it costs so much for you out there, maybe you should convert. Anyway, if the bulb lights up on both sides, its not your switch or freon pressure level, its your compressor most likely. If it is your compressor, write back and let me know. Make sure not to slaughter the wires that you tap into for the test, and wrap w/ electrical tape once your done. Good luck. Oh yea, FYI, there is oil in the cooling system, so if you look for oil stains or cotton weed or air born materials stuck in the evaporator or condensor, it makes job easier.

 

Ok, I think I follow you on all that, I just need to know one thing... where is this switch?

 

Oh yea, my bad. Te switch is located on the low pressure side of the system under the hood. It is the only sensor hooked up to the a/c lines with wires coming out of it. Good Luck!

 

the low pressure switch is located on the accumulator. the shiny cylinder thingy by the passenger side.