First off do you have a manifold gauge set ??...if not you are going to have a hard time figuring out how much Freon to add.,,it’s probably around 26 oz or so...if you jump pins 87 and 30 at the relay does the clutch engage ??..,if it does see if it starts to take the Freon..,if the ambient temp sensor is bad or the AC pressure sensor the clutch won’t stay engaged !!...with the key on back probing the AC pressure sensor signal wire see what the voltage is !!..,it’s a 3 wire sensor...the connector is shaped like a triangle and the signal wire is the bottom one by itself...should not be 5 volts or 0 volts !!...I think mine was not even 1 volt key on !!

 

Did you pull a vacuum and leak check it

 

Yes, have gauges and vacuum pump. Held vacuum overnight.

.

 

I'll check that out, thank you. Not at home right now.

 

Well I vacuumed system again tonight, cleared the codes and reset those parts under the dash that had the code by pulling the fuse. Got it to take a charge, cold ac in driveway for about 30 min. Thought I was victorious so I cleaned up my tools and drank a few beers. Started the car up after it sat for about 30min more not running and what do you know, no ac. Compressor won't kick on. I used my gauges to fill it up and a scale and now the low side reads 350 and high is about 125. I know I didn't over fill it. I used two cans and weighed the other 4oz out of the last can. It was working fine when I shut it off. Thinking I should have it drained out. The readings are with the car off, no ac on.

 

did you put oil in new compressor

 

yes sir i did

 

Well I forgot to check for codes after I gave up last night. I found 5 codes.
PCM- P0530H. I think this is me unlplugging the sensor and plugging it back. Cleared and went away.

A/C- B0332H
B0337H
B0361HC
B0365H
I cleared the codes and they all went away. It took me twice to clear the B0361. Outside temp gauge shows correct temp, not sure how to see if inside cabin temp is working. When I cleared the codes I could hear the actuators resetting.

*Looking up those codes and I found another thread where it was suggested it might be the climate control. Car is an 04 with dual climate.

 

HUH ???....350 on the low side ??...you sure of your readings ??...my system on a 90 degree day with 80 % humidity is 34-35 on the low and around 225-230 on the high...is both are high your system is likely overcharged !!

 

Yes lol, but the high side was super low. Dont even know whats going on. I can say that it didnt read that when I was filling it. After I shut the car off and then went back it didnt work. Thought I would check the gauges and thats when it showed high low side/ low high side.

 

If signal is bottom then there are still 2 other wires. That being said, one of those wires reads .010v, the other 4.9v.

 

OK, I feel like Im getting in deep and doing things I was scared to do, system was vacuumed and held vacuum for 45min. I tried again to fill it and under the vacuum the system started sucking some up from the can but the compressor wont kick on. Only 6-8oz is in the car. I jumped the ac clutch relay (scary lol) and the compressor kicked on. Watched the pressure on low and hi drop BUT the low side is reading 45, high side about 120. Im scared to keep going haha. Its 100* and 27% humidity. Guess I should be aiming for something like 32/325? I dont want to keep filling it if its showing overfilled right now.

 

Looks like a bad compressor to me !!...high side should be 197-271...that’s the high side number for my car for that temp and humidity !!

 

Ok my ex mechanic neighbor buddy is walking me through this via text.
Started with 1 can, compressor on reads 25/200, compressor off looks like it tries to equalize to 80/150. I'm gonna slowly keep moving forward this time not paying so much attention to oz but the gauges.

 

Don’t worry about the pressure with the compressor off...only on !!...the “rest pressure” of 134A should be close to your ambient temp when the car is shut off after about a few minutes when the pressure equalizes !!

 

I've gone through this process twice on C4s, so your mileage may vary. Since you had successful vacuum holding, you might not suspect a leak, but I'd recommend putting in some UV fluid to double check that there isnt a leak somewhere. With a UV flashlight it quickly shows if/where there's a leak. That's how I discovered that my orifice tube wasn't tightened in properly.
You haven't talked a lot about where you added your oil, but it doesn't sound like that would cause you the problems you're having. I found that adding oil in the right amounts to all the components was a PITA.

Good luck!

Paul

 

Dumb question here, but I’m gonna an it. Say you put the dye in your ac system and then get the uv light out and start looking around the ac system. If there’s a leak within the evaporator coil assembly, how could you tell? Without dis assembling the heater -air box?

 

Really can't do it with dye in that area without taking half the dash apart...best with a "sniffer" in that area and they are not real expensive !!

 

Ok, heres the update. Started from scratch before neighbor friend came over. Flushed system and vacuumed for a couple hours. Held good vacuum for another few hours. Neighbor came over and he filled it. He couldnt get compressor to kick on so he jumped the compressor clutch relay. Car took a full charge and is blowing cold air. Cant remember the numbers on the a/c gauges but he explained it to me to help me understand, this was on Sunday so I forgot the numbers. Anyways, compressor wont kick on unless relay is jumped. Codes B0361 and B0365 keep popping up immediately after clearing codes, pulling fuse etc. Pretty sure this is my problem. I know the actuators may need to be replaced and are a pain, but my real concern is what are the chances both went bad at the same time? Never had any problems with them before. Car is an 04 so I think it has the stops in the gears already.

Also like to add that not all ac systems are created equal I guess. 2 shops couldnt get this thing sorted out lol. Glad I didnt let the last shop put in a compressor for $1600 parts/labor.

 

You need to test Relay 34 (the one you jumped). You can swap it with the Fuel Pump Relay, since they are the same, and if the car works fine then Relay 34 is OK.

If Relay 34 is fine, then you need to check voltage at Fuse 24 with key ON. Using a multimeter, check both testing points on the upper edge of the fuse: both of them should have full battery voltage.

If Relay 34 is fine and Fuse 24 has power with key ON, then something else in the controlling side of the relay is preventing the A/C clutch from engaging.

If I were in your shoes, I would like to rule out the possibility of a sensor telling the PCM not to engage the A/C clutch, or the HVAC Controller not being able to communicate with the PCM via Serial Data Bus (do you have any "No Comm" codes involving the HVAC Controller?).

I suggest testing these 2 sensors:

• Outside Temperature Sensor
• Refrigerant Pressure Sensor

The first one will prevent the clutch from engaging if the outside temperature is reported as below approximately 35°F to 40°F, and the second one will do the same if the refrigerant pressures are reported as below or above certain thresholds.

You could test the Outside Temperature Sensor using the attached table, a multimeter, a thermometer and water. A mix of water and ice should provide 32°F and if you remove the sensor from the car and submerge its tip in the water, it should read around 32.6k Ohms. Using progressively warmer water, test it at several points and check its resistance against the table below.





To check the Refrigerant Pressure Sensor, connect your A/C gauges and start the car. Read both pressures at equilibrium (they should be the same) and read the sensor's output at that pressure. Then jump Relay 34 as you did before, and read your high pressure and the sensor's output at that pressure. Compare those 2 sets of values to the ones below (courtesy of C5 Diag ) to verify if you're within the "safe zone" (where the clutch is not prevented from engaging) and if the sensor's output matches the expected values at those pressure points.

Refrigerant Pressure Sensor measured back-probing its Signal (RED/BLK) and Ground (BLK) wires:
Over 410 psi or below 30 psi - A/C clutch won't engage.

Refrigerant Pressure Sensor:

• 5V reference (GRY)
• Signal (RED/BLK)
• Ground (BLK)

These tests won't cost you a cent and they will only take you a few minutes

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