A/C cycling on off

Greetings,

I have a 1989 buick lesabre 3.8 liter FWD. I just install a new 134a A/C system from top to bottom. (compressor, hoses, condenser, evap dryer. ofrice tube pag oil.....). I vacuumed the system for 1 hour and let it sit for 45 min to make sure it held the vaccum. I also have a leak sniffer no leaks. Then i shot it with the 134a freon. My problem is it cycles on and off in 3 second increment. I have a good guage set. the reading when the system is off is 30-low side and 50-high side. Any ideals? I live in south GA and it's hot as heck down hear!!

Thank you

How much R-134 did you add?

1.5 cans

When doing a R-12 to R-134 conversion, you should use only 90% of the R-12 charge specifications, which is: 38.50 / .90 = 34.65 oz. You did not mention the size of the can you used, but typically they are 12 oz; which means, if you only added 1 1/2 cans, (18 oz) you are are very low on refrigerant!

Or if they where the small cans 6 Oz. Either way sounds like you are short on r-134

THANK YOU! I was so low... i added the rest of the freeon and it's blowin snow balls.
a guy in GA riding in A/C!

Next time you go to check the pressure, with the compressor on( let it run for about 10 minutes ) and if the temps are roughly or close to 90F and the humidity is high, look for the low side to be between 40-50 Psi