My car A/C will blow cold air and then it goes warm. It switches back and forth while driving. Suggestions?

Answer 1

Sounds like it is low on Freon. How old is the car? There should be a plate or a sticker under the hood, near the radiator, that says the AC unit requires either r-12 or r-134. r-134 systems also have comparatively large red and blue service caps.

If it is r-12, as in older cars, it should be converted to r-134, because r-12 is practically unobtainable, and very expensive if you can find any.

Most cars have been using r-134 for some time, and many older cars have sometimes already been converted to r-134. If it is r-134, any auto parts store has r-134 and a fill adapter. The fill line should have a blue cap. Remove the blue cap, start the engine and A/C and screw the adapter onto the can, and snap the other end of the short hose onto the fill line. Fill line is often on the passengers side, near the firewall. If AC works sometimes, and then cuts off, one can should do the job, but you may need a friend to rev the engine just a little bit. Hold the can upside down while filling(AC has to be running to fill), and shake a little bit until the can is empty. Quickly remove the fill adapter and replace the blue cap. Also, follow the refrigerant lines, and use two wrenches to tighten any brass fittings.

R-134 and r-12 are NOT compatible. If you have an older car with r-12 refrigerant, to convert it you must completely remove/recover all the old r-12, and vacuum the system down for at least thirty minutes. The change kits are around $40-50. You will also need to bypass the low pressure switch to cause the AC to run and accept the new charge. This is best done by a professional technician unless you have access to a vacuum pump and a knowledgeable helper, but shop around for prices.

Answer 2

If it blows cold on the flat roads and gets warm or hot when you start pulling a hill it's a vacuum leak. The most common places this occurs are the control head, the main vacuum line from the reservoir (if your car has one) to the interior of the car, or the vacuum reservoir itself.

Answer 3

You should check your a/c system to be sure it's got plenty of refrigerant in it. Otherwise, it will either be the a/c compressor clutch circuit or a damper in the ductwork that is not functioning properly. Good luck.

Answer 4

i'm assuming "the a/c motor works" ability the compressor is enticing and turning effective. The gadget ought to be evacuated in basic terms before charging it with freon(134a). the nicely suited quantity of refrigerant ought to charged. the nicely suited quantity of oil ought to be injected. in case you have finished this and it nevertheless does not cool. the undertaking may be the orifice tube or develop block, reckoning on the make of motor vehicle.

Answer 5

You might need to check to see if you have a vacume leak in one of the hose.

Answer 6

check the freeon or whatever cooling fluid it uses. might be low or need to be re-pressurized

Answer 7

Buy a new car

Answer 8

A/C needs recharged.

Answer 9

you have a vacuum leak

Answer 10

freeon