Hey guys I need help diagnosing an A/C problem on my wife's car. It started blowing cold in the mornings then after 10 minutes or so blowing warm air until now it's to the point where it's blowing warm air all the time. So I took it to the shop I've used for years and they told me it was electrical because the freon is fine the compressor is working and no blockage on the evaporator. So I saw a thread on here that shows how to pull an A/C problem code using dash buttons. By the way it's a 4 cyl. Vtec engine. I usually do all my car and truck repairs and am a journeyman electrician so if anybody can shoot me a schematic for the HVAC circuit that would be great! Also if this is a common problem and someone has had this happen to them and fixed it that would be great as well. Thank You! For your time.

 

There can be a lot of reasons why the air blows warm with the a/c turned on. There usually isn't one cause, so it's easier to do some basic diagnostics first.

Open the hood. Find the a/c compressor pulley (bottom and closest to the bumper). The clutch is a metal plate in front of the pulley. Start the engine with the a/c off. Use a flashlight to verify the clutch is not spinning. Turn on the a/c and have the inside the car turned on. Both fans bolted to the radiator should turn on and the clutch should start spinning.

Be careful and avoid getting yourself or your clothing close to the belt as you can get hurt by these moving parts.

I'd get any hvac codes. There is a link in this thread:

https://www.hondaaccordforum.com/for...threads-40780/

 

I had an issue before I knew anything about ac that PAhonda was able to help me out with. I know a bit more now about ac but not as much as I do about the engine operation itself.

Anyway, my issue was my ac expansion valve was bad. What it would do is blow cold for a few minutes then stop altogether. I replaced the expansion valve and all was well again.

If, when you first start the ac it blows cold but then stops blowing cold I would think the same solution would fix your issue too.

You would need to have the system evacuated, remove the glove box, remove the evaporator after disconnecting the connector for the thermometer, and replacing the expansion valve, put it all back together and have the refrigerant replaced. It would be wise to also replace the receiver/drier as well. It's fairly easy to do as it's by the left headlight.