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Evo GeneralDiscuss any generalized technical Evo related topics that may not fit into the other forums.
Please do not post tech and rumor threads here.
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So I posted something similar to this last year, Bottom line I want to get my AC working in my Evo so I do not have to suffer any longer. The closest connector off of the compressor is not plugged In, also when looking up into the bay I found a snipped harness and no connector, while getting work done to my car I asked my tuner to just splice a wire to it and see what happens, well it did nothing.
Fan still turn on/off with AC toggle but compressor does not move, is there a better way to diagnose this? Make sure that wire is correct and is there any other connections I should be looking for besides that one? Also system holds refrigerant just fine. If I have to buy a new compressor I will but I would like to make absolute sure this one is bad since it's kind of a weird situation to begin with, any help is hugely appreciated
Sounds like there is a problem with the AC compressor clutch. Strip the reconnect that wire to the cut harness according to the color code and check the AC compressor relay. I don't know what kind of signal it needs to lock up, but if you are giving it the right signal (probably 12v to energize the AC clutch for engagement) and it's still not locking then there are other underlying issues. This might come down to checking for continuity in the wiring harness as well.
Sounds like there is a problem with the AC compressor clutch. Strip the reconnect that wire to the cut harness according to the color code and check the AC compressor relay. I don't know what kind of signal it needs to lock up, but if you are giving it the right signal (probably 12v to energize the AC clutch for engagement) and it's still not locking then there are other underlying issues. This might come down to checking for continuity in the wiring harness as well.
Okay so you think re strip and connect it myself? Also I will check the relay that I have not done yet
Okay so you think re strip and connect it myself? Also I will check the relay that I have not done yet
Correct, the only thing we can do is work backwards to reverse the damage and use a process of elimination to sort out what's actually gone wrong. Hopefully you won't have to replace the AC compressor as that involves having a shop remove the R134a from the AC lines so that you can service it. After that you might need to replace the AC Drier and then have a shop place a vacuum on the lines to draw out the moisture before refilling with the correct amount of pressure using R134a. Sometimes there are kits that replace the clutch inside the AC compressor pulley, but let's first start with the wiring.
Take a paper clip and put it in the two pins of the harness to the pressure switch and your ac clutch should engage (engine running) if the relay is good showing that you have low or no pressure in the system and have a leak. If it does not engage, that means your compressor clutch is bad and or needs to be shimmed or the power relay is bad ( you can swap the relay next to it to test it)
87076 is what you are looking for under the hood.
This might help looking for wire colors
Last edited by DSMolition; May 8, 2018 at 01:45 PM.
A magnetic clutch cut wire causes me to think the compressor locked up. Engaging the clutch on a locked compressor would fry the belt. To see if this is correct, try turning the compressor by hand.
A magnetic clutch cut wire causes me to think the compressor locked up. Engaging the clutch on a locked compressor would fry the belt. To see if this is correct, try turning the compressor by hand.
I know this thread died, I had to replace my tcase suddenly so I focused on that first... that's fixed now back to the AC lol. I spun the clutch by hand it moves freely with slight resistance so it is definitely not seized
Take a paper clip and put it in the two pins of the harness to the pressure switch and your ac clutch should engage (engine running) if the relay is good showing that you have low or no pressure in the system and have a leak. If it does not engage, that means your compressor clutch is bad and or needs to be shimmed or the power relay is bad ( you can swap the relay next to it to test it)
87076 is what you are looking for under the hood.
This might help looking for wire colors
Do you think still try this even though the "power supply" is crudely wired up currently potentially not even powering it
I know this thread died, I had to replace my tcase suddenly so I focused on that first... that's fixed now back to the AC lol. I spun the clutch by hand it moves freely with slight resistance so it is definitely not seized
The pulley part of the compressor clutch simply spins on a bearing until the clutch is energized. To turn the compressor by hand use a socket on the center capscrew or energize the electromagnet with the engine off.
I replaced my compressor clutch and coil before I found out that the harness between the fuse and the relay was grounding. Fuse had power, relay did not. I spliced a wire from the fuse, to the power side of the relay and TADA.
Might as well say the issue is somewhat found, Everything is wired correctly, System holds a charge and I put a power probe to the compressor, clutch clicks on but does not engage the compressor to spin. Looks like I just need a new compressor/clutch and be done
The nice thing about it is compressor clutch R & R is easily done on car. One suggestion, if you order a clutch from the dealership, open the box before you leave. They supplied me a smashed one.