Rep Power: 0

08 civic. AC had stopped working. Clutch was not engaging. Checked fuses and relays. All good, so I ordered a new ac clutch and installed. Eureka! Cold air. Headed off for a weekend getaway with my wife. Hadn't got very far before it stops blowing. Quick inspection revealed lines frozen clutch not disengaging unless I pulled the fuse. It was engaged even with ac off and heat on. I read thru another post with exactly the same problem and ezone reborn changing the control panel in the dash. I went to the wrecker and tried three control panels. All three did the same thing-- AC clutch did not engage. I've got to think chances are pretty slim that I found 3 bad control panels! right now it's back together with the original control panel but I did bring one from the wrecker home with me. I'm stumped.

 
Rep Power: 224

Check the clutch relay in the under-hood box. Maybe it's stuck on.

 
Rep Power: 0

Done that. Relay is good. Swapped it with others.

 
Rep Power: 224

PCM pulls a signal low to enable the compressor relay. Really can't tell much else from the schematics. Looks like the A/C on/off button signal is going over CAN to the MICU/PCM. Might be a bad PCM. You are welcome to look at the schematics yourself, link below.

http://civic.hondafitjazz.com/manual2.html

 
Rep Power: 0

hmmm, nice diagrams! so much detail that I wish I'd found earlier. The thing that's really puzzling is why the clutch is engaged and stays that way right now, but when I swap out the hvac control panel, it won't engage...

 
Rep Power: 224

I misread your first post, I thought the three others did the same thing where the clutch stayed engaged.

Have you checked the pressure in the system yet? If it's too low the clutch will not be turned on. Maybe the original controls kept the clutch engaged when pressure was low which could cause it to freeze up, then the three replacements were correctly not engaging the clutch?

 
Rep Power: 0

I'll get the pressure checked.