AC is cycling on and off

[fuelman]

AC was upgraded last year to R134, blows really cold then cycles off, then comes back on later, any ideas? I thought the system might have a leak and low on R134, but it blows really cold when it is on?????

 

[Jan Larsson]

It only cycles when pressure on the high side (or was it low side) is low so you might want to check if low on refrigirator or not before doing anything else, or they can use a "sniffer" to see if you have any leaks without much effortr.

 

[TURBO1]

If the system cycles off/on a lot, its usually an indication that the system is low on charge, most likely from a leak. I've seen this a lot with older cars that have been converted, if the conversion was not done right, there could be multiple small leaks, but if there is dye in the system, you could use a UV light & yellow glasses to trace down the leak and/or an A/C system sniffer, but those can be expensive.

On a side note: The R134a is a conversion, not really considered an upgrade on a system designed for R12. An R12 system with R12 will always blow colder than a R12 system thats been converted to R134a.

 

[8289ta]

Fix the leak and convert it back to R12. It is not impossible to find. Check out Craigslist, and you will find some. It is not cheap, but for a few cans, it won't break the bank, and your system will run like it should.