Converted my 80 Elcamino to 134A but needed to know how much 134a to put in it all new parts and put the can in it so far but does not get cold

48ozs

R U Sure? the R 12 systm holds 3.5 and I beleve about 80% of 134 need to be use 30 oz that what in it now also the compressor keeps cycling on and off I was alsotold that I needed to turn a screw in the pressure swith and add a aux fan

Hmmm... My shop manual shows your 80 as holding 3 lbs 12 ozs of R-12 charge, so using the 80% rule my calculation is correct. If the sticker on your car shows 3.5 lbs, by all means use that minus 20%.

Yes, you will need to adjust the cycling switch. You may or may not need an aux fan.

how do you calculate the amount? and how do I adjust the switch the switch is on the drier right do I turn counterclock was or clock wise and how many turns? I will need a aux fan gets hot when sitting still

how do you calculate the amount? and how do I adjust the switch the switch is on the drier right do I turn counterclock was or clock wise and how many turns? I will need a aux fan gets hot when sitting still

Original R-12 charge minus 20%, however, your results may vary as this is meant only as a starting point.

Adjust the switch about a quarter turn counter-clockwise.

How is your fan clutch?

the fan clutch is new and heavy duty ac starts to blow hot when at a light how my ozs is the R-12 can

Depends, some are 12, some are 14.

Robert the problem that Elkzzilla is having with the AC performance may have alot to do with an insufficient air flow thru the condenser and radiator. I had a midyear Corvette with factory air. After I replaced the compressor and changed over to R134A I had problems with the cooling system and poor AC especially at idle, the high pressure side was real high also. After fooling around with it for awhile I found the problem. Some previous owner had "restored" the AC condenser by spray painting the core. He hadn't cleaned the core before painting it. Years of gunk covered by several heavy coats of paint had effectively blocked it. After removing the paint and gunk the AC worked perfectly and the engine ran much cooler also.
Just a thought: sometimes when faced with a problem on an older car that might have had many previous "expert" repairs and modifications you have to think outside the box.

Aha!

does anyone know were I can get a more efficant condensor to the 80 elkie al the ac goes on and off contenusly why I turn the swtch a 1/4 turn back

Do you have a set of gauges, and if so, what are your pressures?

Yes the low side 25 High side 150 after a few minite the high side rises to 300 so i wet the condensor and the temp goes back to 150 or so the air is cool in cab about 45 or so added another can total 3 134a the cycling stoped but when standing still the cab strats to get hot air work good as long as i keep the condensor cool im in az the out side temp he is 90 or so