ac question
 

ok so ive been trying to figure out what exactly the problem is with my ac without having to start throwing parts or freon at it, so first off had it in my school (UTI) and had the a/c class check it out, came back that
low side pressure= higher than normal
high side pressure= lower than normal
a/c clutch is cycling on/off about every 10-15 seconds.
so as far as I can tell i'm either dealing with an undercharged system or a bad pressure cycling switch. i jumped the wires on the cycling switch to keep the clutch on and the air deff gets colder, would that mean its a bad switch? or could it still be undercharged and blowing cold air?

hard to tell what they interpreted as high side lower than normal and high side lower than normal, exact pressure readings would be nice to know???? also with a thermometer you need to measure output from the vents, could be a bad compressor, which is generally how readings as such are interpreted, or possibely a restricted orrifice tube, watching the psi readings would be of great help in this instance

ya i wasnt in there to see the guage readings, i am hoping to get some on myself soon. and i dont believe it would be a bad compressor because it wouldn't be causing the comressor to cycle on/off like that, and the orifice tube seems good, it changes temp after it so more than likely its in good condition

my bet is whomever read the gauges, read them wrong or had them hooked up wrong, on some r-12 systems often times the service ports had the same size fitting, can't remember if my old r-12 system on my mustang did, cause the low pressure switch/a/c cycling switch cuts compressor action when pressure drops below 24 psi iirc on the r-12 system employed in the mustang so if low side was higher than normal it would cause the compressor to run continually not cycle on /off, my bet is all that is wrong is your are low on refrigerant :)........some r-12 systems employ a sight glass, once again not sure if the mustang has one but in the case it did, viewing the sight glass and seeing bubbles in there was often a sure indication of a low charge:)

not going to your local auto store and buying 12

some freeze 12 ftw!! :)

i need to take my refrigerant quiz so i can buy the r12....my brother took his a few days ago

r-12 iirc only comes in 30 lb cylinders and is not cheap, why waste the money on r-12, convert to 134a

Here is a bit of history. Not sure if it is true. Goes like this Du Pont patent ran out on R-12. Now the replacement gas 134-A. Guess who has patent on that? Du Pont. Convert to 134-A is easiest way to have A/C and obtainable gas.

no you can buy r12 in cans...and off ebay(they require the number to sell it to you) and stuff like the compressor(Hr980) on my Notch is not suitable for r134 i just ordered a Ford Compressor and clutch and dryer.

im actually fixing my AC this week on my Notch, i sold my 5.0 vert im down to three stangs now the 65,89,95