Kia Sportage AC still not blowing cold after compressor replacement.
Hi all!
My fiancées 120k mile 2011 Kia sportage 2.4L has had a broken AC for a couple years now and we’re finally (sorta) in a place financially to do something about it. We got a diagnosis done and they said we needed a new compressor. From what I saw, the clutch was engaging but the low side pressure was about the same as the high side pressure.
We got several quotes and definitely couldn’t afford them, so I went ahead and bought a four seasons compressor and expansion valve kit + a GPD condenser from rockauto to do the repair myself. I removed the 3 parts, along with the discharge hose that had slight damage, and flushed every reused component until the solvent was coming out clean. There were initially metallic bits throughout the system, so I think the compressor grenaded and definitely had to be replaced. I then reassembled using the proper amount of oil, replacing every oring, and doing a successful vacuum leak test.
I thought the whole process went great, but when I brought it back in to be recharged it didn’t work. No cold air no matter what AC setting. Both high and low pressure lines remained hot. The clutch engaged without issue but the low side pressure was still pretty much equal to the high side pressure.
Initially I thought I just got a bad four seasons compressor since the clutch was on but there was no compression happening. Now I’ve discovered the compressor has an electronic control valve and I’m concerned the vehicle may not be trying to turn the compressor on via the ECV. What are the odds I got a faulty new (not reman) compressor vs the odds I have ECV control issues? Is there a way I can rule out one issue without filling the system again? Each time I recharge and recover I have to pay a mechanic and the system is current evacuated. Are there any other failure modes that could cause this same behavior that I don’t know about?
To rule out ECV control issues, I am thinking of unplugging the compressor, bypassing the pressure switch with ~3V, enabling the AC, and probing the ECV control lines with an oscilloscope. I believe I should see a PWM signal matching the AC demand, correct? Does that procedure sound safe/correct?
Anyways, sorry for the long post and thanks for any advice you’re able to give!