A/C Problem

[martattack]

The hits don't stop coming...

For some reason my A/C isn't working right now.

I just replaced the wiring harness, and after that, the car ran fine.
Couple days later, I notice the auxiliary fans are running far more often than normal. I have been driving around with the A/C on lately. Coming home from work the other day, I noticed the A/C was not blowing cold. I checked to see if there was a drop in RPM at idle when the compressor kicks in, and there is not.

I do notice that the compressor turns on for about 1 second as soon as I start the car with the A/C on, but then it shuts off and doesn't run.

Could this be one of the refridgerant sensors? I hope to everything hholy that my Compressor is not going out.

Any experiences and ideas?

[nokia8860]

Does your ac work for a bit then turn off and if you shut your car down and power up the ac will work again but for a short time then shut down again?

[martattack]

Originally posted by nokia8860
Does your ac work for a bit then turn off and if you shut your car down and power up the ac will work again but for a short time then shut down again?

exactly!
Only for a couple seconds though. not even enought o pump any cold air.

[nokia8860]

Check your evaporator temp sensor.

[jnenad16]

as nokia said, evap icing sensor, but it could also be compressor speed sensor(back of compressor), or the pressure sensor, they all have the function to switch the comopressor off, and then there could be the control module itself(hopefully it isnt).

nenad

[martattack]

Is there any way to check these sensors by measuring the resistance? Or is it a shot in the dark as to which one isn't working?

[jnenad16]

well, you can probably run the ac system diagnostic through the pushbutton module, and it might give you the code.

nenad

[martattack]

Originally posted by jnenad16
well, you can probably run the ac system diagnostic through the pushbutton module, and it might give you the code.

nenad

I don't think I can because I have the older style climate control with the small screen and big buttons.



By the way, is this the A/C temp sensor that was being spoken of?
http://img.eautopartscatalog.com/live/R107526553BEH.JPG

Or was it the evaporator temp sensor that looks like this:

http://img.eautopartscatalog.com/live/R107186215ACM.JPG

[jnenad16]

the first one is the ac kill switch, when the coolant gets too hot, if the compressor is on, it will get shut off( I guess I forgot about that one), and the second one is the evap icing protection sensor, which shuts off the compressor when the evap gets too cold.
even the older ac control modules can perform the self diagnosis, I'll try to find the procedure and post it.

nenad

[jnenad16]

http://img.photobucket.com/albums/v624/nenad16/C280acdiagnostic.gif
http://img.photobucket.com/albums/v624/nenad16/c280acdiagnosticlegend1.gif
http://img.photobucket.com/albums/v624/nenad16/C280acdiagnosticlegend2.gif
http://img.photobucket.com/albums/v624/nenad16/c280acdiagnosticlegend3.gif
http://img.photobucket.com/albums/v624/nenad16/c280acdiagnosticlegend4.gif
http://img.photobucket.com/albums/v624/nenad16/c280acdiagnosticlegend5.gif

nenad

[benzdude280]

:werd: That's an awesome write up. Thanks.

[martattack]

Well, I did that and I got a code 49 as a current code, and a Code 60 as stored.

So that means my Aux coolant pump is dead and my compressor clutch isn't working?

Damn. I'm going to try running the Aux water pump manually with jumper wires, and also try jumping the compressor to see if it runs correctly.

Any other ideas on the situation would be helpful!

Martin

[Sulaco]

Holy shizzle. Thanks for the instructions nenad! You are a life saver.

But look at my list of codes...

Constant codes:
24
26
28
62
60
80
82
92

Intermittent codes:
102

What the hell? My A/C works except for the center vents shutting off and diverting their air to the defroster from time to time.

[Sulaco]

Okay, so I'm going to assume 3 of those codes that refer the the "switchover valve block" are talking about that black box on the passenger side near the OVP that handle all those vacuum lines. I know it has a crack in it.

2 of the codes are talking about the electromagnetic clutch on my compressor. (But my compressor works fine, I think).

But 3 of the codes refer to the engine coolant temp sensor. Where is that? Can I replace it?

[martattack]

Originally posted by Sulaco
Okay, so I'm going to assume 3 of those codes that refer the the "switchover valve block" are talking about that black box on the passenger side near the OVP that handle all those vacuum lines. I know it has a crack in it.

2 of the codes are talking about the electromagnetic clutch on my compressor. (But my compressor works fine, I think).

But 3 of the codes refer to the engine coolant temp sensor. Where is that? Can I replace it?

Those codes have probably been stored there forever. Erase the codes, drive around for a bit, then run the diagnostic again and see if they still pop up.

Martin

[Sulaco]

I deleted the codes and drove around for a bit yesterday. Only code that returned was 060: compressor electromagnetic clutch. But if my compressor is working fine (to the best of my knowledge), why would it send that code?

Could the fact that something else is wrong with my car (wiring harness and probably TBA) causing it to run like SHIT when the compressor is on make it think the compressor is malfunctioning?

[Abuimad]

jnenad16 that was an amazing write up wich helped me alot, thank you soo much, you have no idea how gratefull i am

[Perinchery]

Nenad...
My A/C does not work..I mean the blower works fine...except it does not blow cold air....The compressor does not kick in...
I pulled the following codes fm my A/C unit...
No Continous codes....
Intermittent Codes...
23o2
23o3
41o6
41o7
41o9
42o1

I couldn't figure out how to read these codes...
Code 23 in your write up talks 'bot Engine coolant temp sensor short ckt...But then wots the 23o2 and 23o3...??
And there is no code 41 and 42 in the writeup...
Any suggestions are appreciated...

96 C220

[jnenad16]

Originally posted by Perinchery
Nenad...
My A/C does not work..I mean the blower works fine...except it does not blow cold air....The compressor does not kick in...
I pulled the following codes fm my A/C unit...
No Continous codes....
Intermittent Codes...
23o2
23o3
41o6
41o7
41o9
42o1

I couldn't figure out how to read these codes...
Code 23 in your write up talks 'bot Engine coolant temp sensor short ckt...But then wots the 23o2 and 23o3...??
And there is no code 41 and 42 in the writeup...
Any suggestions are appreciated...

96 C220
Check the coolant temp sensor plug, it might not be securely plugged in, but if thats the case, the CEL should be on. next thing to check is the pressure sensor, see if it too is securely plugged in. if it is, my next guess would be low freon. connect the AC manifold to the service ports(or have a shop do it for you) and see the system pressure.if that checks out, then its the time to check the power supply to the comressor, if there is power, the clutch is the culprit, if no power, it could be one of the following: bad coolant temp sensor, pressure sensor or the control unit itself.

nenad