2G A/C system not working

[cswindel]

Alright electrical nerds I need to be graced with you assistance as I am no good with electrical.

Current situation:
- A/C is not blowing cold air although the system has been charged recently without the system actually pulling in r-134 because well it dont work haha
- I dont have any prior knowledge of whether it worked or not before or after my teardown of the car
- As a side note I am running OHM harnesses throughout the engine bay and interior and running ECMLink v3

Current untested areas and possible theories:
- A/C compressor is dead and I have not ran 12v power to it such that I can test if the clutch engages or not
- Seeing if there is a setting in ECMLink that I am missing since the a/c and rad fan both kick on when signal for rad fan to kick on gets pushed out
- Thermo sensor is poop but havent checked and the wiring diagrams confuse me on where it is physically located behind the glove box and there arent really any pictures when i look.
- ACCU is poop but havent checked and not sure which wires in the connector to check but havent dug into that area yet because its a pain to reach

Steps I have taken thus far:
- Checked continuity from ECU pin 22 to A/C compressor relay in fuse box (Good continuity)
- With key in ON position and engine not running, I have voltage going to the a/c fan (connector A-39), Dual pressure switch (A-47), and the A/C compressor (A-95)
- With the engine running I checked for voltage at the same connectors and nothing concerning
- With the engine running and a/c switch active I checked voltage again and still nothing concerning. A/C compressor ground showed grounding too.
- With the engine running, I jumped/bypassed the dual pressure switch and no result came about from that
- As mentioned prior, I noticed that the a/c fan and rad fan kicked on at the same time when the signal for the rad fan got passed through the circuit (I dont know if this is normal or not but hey 2 fans is better than 1).

Just wanting to see what your inputs are with this matter before I start going down unnecessary rabbit holes without much guidance (because I will get lost, sad, and confused and it might all occur simultaneously). I believe I have covered the majority of what I have done and assessed to get this thread rolling at least

 

[cswindel]

Few tips to add/check:
I noticed you said you have the OHM harness and I am not sure about the 2G but on my OHM 1G harness they do not wire these for A/C. Would start here for sure
Does the evaporator blower fan come on
Could be just a bad pressure switch
Does sound like a blockage more than likely a TXV, could try to unclog it by using some nitrogen and blowing the clog out. Would have to disconnect the tubes. usually 200-300 psi is a good start
When pulling a vacuum its not so much about time as it is about reaching the correct Micron target using a Micron gauge which 500 Microns is the standard for all A/C systems, as at this state it turns water to vapor and it also ensures any trapped moisture boils off into steam and exits through the vacuum pump

If it was me I would definetly look at the OHM harness First > Do a pressure test with Nitrogen to check for leaks "keeps from wasting money on R134A if you have a leak" > depending on Nitrogen Pass/Fail> would replace parts that failed TXV, Drier, condenser, evaporator, O-rings. or just replace all the parts as the evaporator is under the dash and not fun to remove and replace.

To help with the pressures and temperatures refer to this chart.

You must be logged in to view this image or video.

Yeah so that's the weird thing is they wired it for a/c but after i did my continuity test they basically ghosted me again and left me with best of luck but that doesn't explain why the a/c fan only kicks on when the rad fan gets signal to kick on. Although I've never seen the a/c fan kicks on independententry because well the a/c hasn't been operational

 

[Vladimir]

Didn't check for condensation. The high side lines got pretty darn hot. And yes I did notice the air was actually getting colder in the cabin

Ok, that's good we have to trace wires and see what's the difference between harnesses. Find the A/C relay and see if there is power at Pin 86 when you press the a/c button on. Pin 85 should be ground, pin 30 constant 12v, pin 87 goes to control

 

[cswindel]

Ok, that's good we have to trace wires and see what's the difference between harnesses. Find the A/C relay and see if there is power at Pin 86 when you press the a/c button on. Pin 85 should be ground, pin 30 constant 12v, pin 87 goes to control

Okay sounds good! Im assuming the car needs to be running? Or just key ON

 

[Vladimir]

Okay sounds good! Im assuming the car needs to be running? Or just key ON

Not necessarily. The ignition must be ON and the A/C button pressed. Try both ways, you should be getting 12v on pin 86

 

[cswindel]

With key in ON position and whether ac is active or not pin 30 gets 12v and pin 85 has 0.05v

 

[cswindel]

When car is running and ac button is pressed pin 86 gets 0.01v

 

[Vladimir]

Ok if Pin 86 is not getting voltage it's not gonna energize the relay to give power to 87 and transfer it to clutch. The problem is in the control side. I'll need to see diagrams to continue. Do test one more thing tho. Is there a good continuity between pin 87 and the 12v wire on a/c clutch? If you don't want to crawl up underneath just jump power from pin 30 to 87, the clutch should click, that will verify that the circuit from relay to clutch is not damaged.

 

[cswindel]

Jumped it and it worked!

 

[Vladimir]

Jumped it and it worked!

Great. The harness going to clutch is good. We will figure out controls next. I'm working now. Had to do side gigs as I broke one of my ribs at the shop. I gotta log in to identifix or something to get diagrams to continue once I'm back home from doing Uber and Walmart orders and other BS. That's why I even downloaded the DSM app I haven't been on it in years, just got bored

 

[cswindel]

Great. The harness going to clutch is good. We will figure out controls next. I'm working now. Had to do side gigs as I broke one of my ribs at the shop. I gotta log in to identifix or something to get diagrams to continue once I'm back home from doing Uber and Walmart orders and other BS. That's why I even downloaded the DSM app I haven't been on it in years, just got bored

Dand man im sorry to hear that but im glad you're here! You're help has been greatly appreciated so if nothing else just know that as a result of all of this you are helping a struggling DSM'er immensly haha

 

[pauleyman]

I gotta ask, fan was on?

 

[cswindel]

I gotta ask, fan was on?

No the fan never kicked on and I mentioned that to Ohm when I was talking to them but they never said anything about it. Only time I've seen the a/c fan come on is when the rad fan kicks on to cool the rad

 

[pauleyman]

No the fan never kicked on and I mentioned that to Ohm when I was talking to them but they never said anything about it. Only time I've seen the a/c fan come on is when the rad fan kicks on to cool the rad

I mean the fan switc in the car. If switch is off ac is off also

 

[cswindel]

I mean the fan switc in the car. If switch is off ac is off also

Oh yes yes the fan and blower motor operate just fine. The knob and fan have always worked on the car that I do know

 

[Vladimir]

Ok I ask my brother to log in at home. I would look the diagrams tonight around 2am but meanwhile here for you

You must be logged in to view this image or video.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

Supposedly this is automatic controls

You must be logged in to view this image or video.

 

[Vladimir]

This is manual control

You must be logged in to view this image or video.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

 

[Vladimir]

I haven't check any diagrams yet but maybe you can start or examine them. We can go from here now later.

 

[Vladimir]

Ok. So the system might be a little bit more complicated. I'm not sure why all the diagrams are getting downloaded like crap with horrible resolution, but I'm gonna try to attach another set in this post.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

You must be logged in to view this image or video.

The first thing that we should probably establish is if in fact your model DSM has two different control modules for the A/C system. I have circled the module that should be located in yellow. Verify please that your vehicle does in fact have this module. It should be in the glove box next to blower motor and it should look like the one on the picture attached .

You must be logged in to view this image or video.

You must be logged in to view this image or video.