Ok, the air conditioning was working just fine. then all of a sudden it started blowing hot air. i hooked up a gauge and it showed it was overcharged.

what would cause this to all of a sudden happen? as far as i can tell everything seems to be working fine. but i am not very experienced with ac.

if you know i would appreciate the help.

 

This happened on a friends car, the blowing cold then one day blowing hot. What had happened was the valve that closes and keeps coolant from flowing through the heater core had broken, so hat coolant was flowing through the heater core and the cold air from the AC was blowing past it and being warmed up. Might want to check it depending on the year of your car.

Thanks, J

 

could also have have a leek and all your freon is gone. but you said it overcharged, so hmm...

 

id wager your expansion valve is shot.. does the compressor continue to run while you're reading pressure? Probobly not because if it was it would popoff (little popoff valve on the side of the compressor) which means your high pressure cutoff switch is still working.

also what psi's are you seeing on the high/low sides to make you think its overcharged??? You should see about 25-40psi on the low side (depends on temp of system etc) and 150-180psi on the highside. if you can give me those #'s i can help a lot more.


[Modified by GimpyAccord, 6:38 AM 9/10/2002]

 

If the system is overcharged, it can blow cooler than 32f. If that happens the water that usually drips to the ground can freeze in the cooling fins on the evap. The air blowing will be warm, humid, and nasty. When the water melts away its back to normal. It thats the problem, dont put it to max cold, try just a little warmer, or maybe use fresh air so it doesnt blow as hard. Those are tips to help prevent it and may not necessarily work. Correcting the amount of refrigerant should fix it.

 

Thanks for the help so far...

When I measured around 110psi it was on the low pressure side.

[quote]
id wager your expansion valve is shot.. does the compressor continue to run while you're reading pressure? Probobly not because if it was it would popoff (little popoff valve on the side of the compressor) which means your high pressure cutoff switch is still working.[QUOTE]

I never heard any popping or noticed anything from the compressor. How would i test if the expansion valve is shot?

It doesn't blow cold air at all. It also doesn't have any type of a leak on the ground like you were describing.

Thanks for the help..any other ideas??? no a/c sucks in the summer

 

If there is low pressure, it will not let the compressor run. Does yours? From here you need gauges to see the pressures and diagnos any futher problems. The pressure should be checked with the engine running. It could just be under charged. If it cycles quickly on off on off on it probably has low pressure, undercharged.

I have gauges and Im in SD. If you want some help e-mail me.

 

Or you could possibly have a blockage on the low pressure side! You need to post both the high and low side reading to get a better diagnosis.

 

yeah, i don't have a gauge to read the high side

 

you gotta read the highside for us to help...

right now with what you're telling me i'm guessing the seals in the compressor are SHOT or the expansion valve is SHOT.

find someone w/guages to read both sides and post the #'s. if the low/high are the same.. prolly compressor. If low = high and high = low expansion valve. That have always been my findings when fixing AC's on hondas.

 

im a little confused on that.

it seems like your saying the same thing. for the compressor you are saying when lo and hi are the same. then for valve you are saying low=high and high=low. wouldn't that be the same two things?

im lost

 

Let me be a lil clearer, sorry.

If you read LOWSIDE= HIGH, HIGHSIDE=About the same as the LOWSIDE= probobly compressor. (pressure leak in the compressor allowing seep)

If you read LOWSIDE=HIGH, HIGHSIDE= LOW, proboboly a bad expansion valve. (not opening).

 

either wat he said or ur compressor is not turning on at all..
start the car and have some one trun on the a/c the compressor clutch should click..if not the the clutch could be bad

 

ill try and get ahold of a gauge to test the high pressure side. ill let you guys know what i get from there.

thanks for the help