I recently purchased a evo 9. I noticed the ac doesn't work. Here's what I've done in diagnosing it.

-First checked if it needed a recharged, no it doesn't it's reading 80 psi
-checked if compressor is kicking on, no the clutch isn't engaging
-checked all fuses associated with the AC, all are fine
-looked on evom for common issues. Found info on clutch gapping and giving the compressor clutch a love tap with a tool to kick on. Love tap didn't work.
-also found on evom sometimes playing with the climate control and defrost will trick it on. Did not work.
-check to see if the ac compressor is getting power at the connector it is NOT
-followed wire under radiator support to fuse box. Checked wire for power right off the box. it does NOT have power after box
-checked fuse again, also checked relay by swapping it with another relay. All was fine.
-thought the compressor switch was seeing it's high PSI, so I took off the connector put a paperclip in the connector to trick it. Didn't work.

With that said. I'm stuck, I'm frustrated. Why isn't the connector seeing powere to kick on the clutch?! What am I missing or should I check now? I have a spare ac compressor but don't want to drain the system if it's really some sort of electrical and not the compressor itself.

Any help is appreciated. Please read my full post so you don't suggest something I've already tried.

 

Sometimes you just have to give-in & take it to qualified AC mechanic

 

Yeah if I cant get it within this week, Im going to. Id def prefer to do it myself. I enjoy doing all the work to my cars myself. Plus side I know the quality, and it was done right. Appreciate the input however.

 

The shop manual states the best way to know that the system has the proper charge is to evacuate and fill it with the proper charge (I suggest including dye). With a proper fill, if that doesn't fix it you then can test and search for other problems without wondering about charge and you don't need special A/C gauges and equipment.

In my case, once the shop had inserted the proper amount of refrigerant, I was able to complete all other repairs the system needed.

 

Did you ever get any resolution on this Tmosser? I'm having the same exact problem. I was just about to post up for guidance/suggestions on where I should be looking, when I came across this thread.

So ill preface this by saying my A/C had been working perfectly no matter how hot the temperature outside and it worked for extended periods. I had no issues. Then today I was running the A/C and I downshifted to 3rd to pass, did a short pull and eased back into cruising speed . Right from that moment the A/C started blowing hot and it never came back to cold. Like OP I checked fuses and relays, they're all good. Checked the clutch gap and tried the tap, nothing. Tonight I checked for power to the coil and I have none. I understand your frustration 100%. Did you get yours sorted?? Anyone have any advice? Thanks
Mine is also a IX with 108k miles

 

No I haven't, next I am going to take it in to get flushed and recharged and see if that fixes it before swapping any parts. I have a spare compressor and high pressure switch if needed. Just would suck to recharge it to release everything swapping either but maybe a shop can figure something out when looking at it I'm not seeing.

 

with the ac turned on are you seeing ~12v at the pressure switch?

 

I came across this and I think it may be a good starting point for our problem. I def feel its not mechanical but a malfunction somewhere caused the circuit powering the compressor to be shut off. This seems to confirm it. Im out of town working for the week but I will start here next weekend when I get back.

 

Turning it to defrost or defrost/feet didn't turn my compressor clutch on.

 

I had the same problem as described here. I'd end up tapping, and the A/C compressor still wouldn't engage. Checked all switches and all had power, and relay was fine. My issue ended up being solved by just removing the shim all together.

https://www.evolutionm.net/forums/ev...-problems.html

Edit: nvm, disregard post. Didn't see that the compressor isn't getting power.

 

maybe wiring, climate control or a relay is bad, i need ac soon!

 

Well that section just basically says when the defrost is selected its just like pressing the A/C button to turn on the A/C. I was most focused on the table below that says if any of those switches on the left are "off" then the compressor circuit will be de-energized by the ecu.

 

so when you turn on the A/C it sends a 12v signal to the pressure switch. If the pressures are within range that signal is passed through to the ecu, which then sends a signal to the A/C pump clutch. I asked if you where seeing that initial 12v signal at the pressure switch, which you haven't responded to. It doesn't matter if you jump that pressure switch if its not getting the 12v signal in the first place.

 

I musta overlooked your post, sorry. I will check that today and get back to you.

 

yah no worries, i figured thats what happened since it was so short and buried between some huge posts.