A/C Starts off Cold then Turns Warm
 

My A/C is a bit fickle. What I notice is that it starts off cold, but then it just starts blowing warm air. When underneath the car I noticed that one of the hardlines was pinched about halfway closed. I don't know if that impacts the system or not though.

I'm not too knowledgeable about A/C systems, can someone lend me some answers to what my problem is?

Thank you!

My best thought is that it probably needs to be recharged, there might be a leak where the line got crunched. Might be slightly compressing a bit of the refridgerant then it might not have enough pressure to keep the cycle going with mostly empty lines, i would inspect it for a leak, see if there is a pressure check valve or replace the line and get it recharged.

I would replace whatever is pinched, that can cause to much pressure in the system and cause bad things to happen.

Thanks for the responses.

Would like to hear your feedback. Better to purchase the OE replacement hardline or to take it to an A/C shop and have them replace and pressurize the line?

Depends on how good you are with mechanics.

I took my AC to the AC place and they replaced all the Orings and a few crimped spots, I paid 240$ for everything, thats converting it to R134 from R12 and it blows Ice in 110 degree GA weather.

Which line is pinched? Are the fans on all the time? What's the history of the system? Has someone who doesn't know what they're doing been adding refrigerant to it? How long does the system run before getting warm? Does the compressor stay on when these warm episodes occur?

Get the pinched section replaced and go with R12A (replace the o rings too) as the R12A is more suited to the system. The pinch is most likely acting as an expansion valve and is causing the system to run hot as you are experiencing.

Not an ac guy but had the same thing happen to my system.

i just converted my SSM to R134 today, with these cars the AC compressor will not kick if the freon level is low, recharge your system but remember to use R134 with oil in it.

If you are running a Power FC, you could be running into the common Power FC A/C problem.

This is also emblematic of the classic thermoswitch problem at the evaporator.

indeed, if it is super cold for the first 5mins then gets completely warm, it is the evaporator thermoswitch. easy to test, just jump a little switch behind the glove box.

mine has been broken for a few years now, I plan to fix it next week since this 40 days of 100 degree weather here in texas is really unpleasant, even at night