Ok my 2002 ta's ac is ice cold on a cool day around 65 60f and blows cool on a day around 70 75f. The dryer is getting pretty cold and sweats also the pressure readings are 30 for the low side and around 200 for the high side the accumulator look to be very clean. Anyone have any idea why it's only blowing cold on a cooler day??

 

I your ac compressor cycling on, your pressure sounds a bit low. If its is 75 degrees out it should be blowing at least 35 degrees colder out of the vents if it is working properly.

 

Yes the compressor kicks on and stays on, you think the freon charge is low?

 

because you are low on refrigerant and ac performance is reduced and it can only handle light heat loads... like when it's colder out.
assuming your ac has never been touched, the car going on 13 years old so having lost an ounce or two of refrigerant over that time period is normal. i had to put a couple ounces in my 2002 ss couple years ago.
what you are seeing with ac working well at night or on colder days but not on hot days is the typical symptom of slightly low refrigerant, you just need to add 1-3 ounces, be careful not to overfill. when using a little 12 ounce can of r134a, you are using at most a 1/4 of the can so it will seem like you didn't add any.

 

Well I just added a little 134a and that didn't change anything, I know I have a proper charge according to the gauge readings... still no cold air

 

I knew this post was coming....................take it back out you have other problems. You may be over filled to start with, next warm day take the pressure reading while the problem you have in happening. Very possible the heater door isn't adjusted properly also check for blockage out at the condenser. Another good test is check the inlet and outlet temp of the evaporator. Touch the inlet and outlet at the same time, they should feel equally cold, very cold.

If the evap is cold as ice and the air coming out the vents is warm you know you have some kind of air door problem OR the seal on the heater core is leaking warm air into the system. Sometimes the rubber foam seals break down then you can get warm air into the ducting when you are not asking for it.



Pressures depend on ambient<outside air temps > but you should be in the 30-36 zone on the low side and 200-250 high side. But a lot of thongs can effect these temps including the air inside the car.

Its also very possible you have a compressor problem but to diagnose this you need to check the pressures as you experience the problem. The control valve in the compressor maybe stuck, dirty or damaged causing minimal cooling. I had this problem last season. The valve was sticking and I couldn't get full output from the compressor. Was cold enough on a 75 degree day but above that the air coming out was just cool not cold.

You will see this problem with pressure gauges as low high side pressures and high low side pressures. As the temp outside rises the compressor would normally increase high side pressure and lower low side pressure to keep up with demand. So if you checked pressures at 70 degrees and saw 32 low and 200 high at 90 you should see 34 and 225 or more. If the valve is stuck you will see 36-38 psi at 90 ambient on the low side and 200 on the high side. I hope this helps you understand the system better.

These newer systems use a valve in the compressor to control system pressures.

 

did you ever get this problem resolved?

 

Could it be a partially clogged evaporator core?