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[RESOLVED] A/C clutch not engaging

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Unreal89

Probationary Member
29
0
Jul 25, 2004
Citrus Heights, California
Hello fellow DSMers.

I am having a problem with my air conditioner clutch engaging. It used to work fine, then after my 6 bolt swap it seemed to cycle for long periods of time ( on for 2 minutes, off for 15, then repeats ).

Things I have done/observed:
Checked the system charge, its fully charged
A/C clutch engages when given 12v directly, blows cold
A/C relay and fuses are good
A/C relay not getting power
Shorted the dual pressure sensor and temp sensor on the compressor to eliminate them as an issue, still no go.
Tested resistance of the FIN temp sensor, OK
Tested resistance of the blower resistor, OK
Checked the ACCU (AC control unit), it looks brand new, nothing burnt or shorted.

I know that there is a way to check if the ECU is grounding the relay, but I am not sure how. I dont not want to destroy my EPROM ecu with dsmlink, so does anyone know how to check this?

Or if anyone has any other suggestions (other than ripping the whole thing out), please let me know.

Thanks!
 
I`m not sure if ecmlink has the ability to log a/c.request. I think it does. With the car running, start ecmlink, & turn on the a/c, & see if you can find a/c. request or a/c. compressor on/off in the data log section. If it is commanded on & still does not engage the compressor (by grounding the relay),then I`d say you have a wiring issue between the ecu.& the relay in the ground circuit. It it does not display a/c.request,then there`s an electrical fault before the ecu ( pressure switch, evap.sensor, etc.)

Edit . . .

I just re-read your post :

If the a/c.relay is not getting power, then you must resolve that first. If no power is available at the relay, then there`s no power available to send to the comp. clutch when/if the relay closes . . . :talon:
 
Thanks, I'll try that in a little bit.

In the mean time, I just remembered I missed something. Right behind the glove box, I have two connectors, one blue, one black. The blue one is not connected, the black one is connected to the FIN temp sensor. Any one know what the blue connector is for? Both connectors have 2 yellow wires.
 
I believe that 95's have a different ACCU than other years. Our setup is similar to the NT's where the ACCU is on the bottom of the blower, where as the newer cars have the ACCU built into the FIN temp sensor connector. Any one with a 95 willing to confirm this?

Thanks
 
Yeah, I've been following a similar document thats on the DSM service manual CD. I think I'm going to have to recheck everything and trace each wire... I wish I did this in the winter, its so hot out, haha
 
Yeah, I went to the pick n pull, and found no 2g DSMs :(.
BUT I found an identical ACCU from a Galant, a similar one from another galant, and another similar one from a dodge stealth. I tried the one thats identical, and CLICK the A/c worked :). Then I tried the other two, and to my surprise they worked as well.
Bring on the HEAT! :D

Thanks for your help, TALONTRAX.
 
Its really easy to locate. It on the bottom of the blower behind the glove box. It has two plugs going to it, it says "AUTO COMP CONTROLLER" on it. You don't even have to remove anything to see it.
 
I just had the same problem of compressor cluch...

Just opened the AUTO COMP..... module below the glovebox....

It has 4 capacitors 10u 25v...

15 year old car, all capacitors have "white hair" kkkk

and you know that the surface of capacitor need to be perfect flat ! all of them, even the ECU etc....

as this capacitors are too small is difficult to check that they all are flat... i was in doubt, and replaced all 4..... even if you see that 1 is convex and others not, REPLACE ALL !

Fixed in 5 minutes !!!

i started to replace all capacitors of the entire car, just missing these ones....

Done !!
 
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