Need some help with my A/C PLEASE

[AK49BWL]

Have you tried yet just plugging in the sensor and seeing if anything happens? If the circuits are good, the compressor will work even without that switch being in contact with the Freon... Its cutout is activated by high pressure after all.

 

[SUBURBAN5]

Also until you connect the pressure switch understand the compressor may not come on until then. Right now you have to test it as if you have the key in the accessory mode

 

[SUBURBAN5]

My bad meant on mode but not engine running

 

[AK49BWL]

Man I really hope you can track this down cause I'm having the same issue with my 06. Replaced every component of the a/c system from the condenser to the controls and the compressor will still only come on if I jumper it at the relay.

I have doubts that what fixes his will work the same for yours.. It's marginally possible tho. I'm only guessing your 06 is a full size, in which case your system has a low pressure switch on the dryer that connects the HVAC controller to ground when the pressure is above the low cut-out pressure (normal operation). Then you have an A/C pressure SENSOR, a 3-wire sensor that tells the PCM exactly what the operating pressure is of the high side. Everything else is Class 2 Serial between the controller and the PCM. Your problem will likely be different. Have you verified the system pressures?

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[GreenZ98]

I have doubts that what fixes his will work the same for yours.. It's marginally possible tho. I'm only guessing your 06 is a full size, in which case your system has a low pressure switch on the dryer that connects the HVAC controller to ground when the pressure is above the low cut-out pressure (normal operation). Then you have an A/C pressure SENSOR, a 3-wire sensor that tells the PCM exactly what the operating pressure is of the high side. Everything else is Class 2 Serial between the controller and the PCM. Your problem will likely be different. Have you verified the system pressures?

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Yep 1500. All the pressures are good, I replaced everything then had an a/c shop charge it. Low pressure switch at dryer has been replaced. Only way to get compressor to turn on is pull and jumper the relay and it'll blow ice cold when it does run.

 

[AK49BWL]

Yep 1500. All the pressures are good, I replaced everything then had an a/c shop charge it. Low pressure switch at dryer has been replaced. Only way to get compressor to turn on is pull and jumper the relay and it'll blow ice cold when it does run.

I'd pick up an OBDII scanner and see what your PCM is getting as far as whether it's seeing the A/C request signal and A/C pressures properly. That's the only way forward on this one.

 

[GreenZ98]

I hone

I'd pick up an OBDII scanner and see what your PCM is getting as far as whether it's seeing the A/C request signal and A/C pressures properly. That's the only way forward on this one.

I honestly don't know why that hadn't even crossed my mind. I'll get the guy in the truck shop at work to do that for me tomorrow. Appreciate it.

 

[Bigred81]

I hone
I honestly don't know why that hadn't even crossed my mind. I'll get the guy in the truck shop at work to do that for me tomorrow. Appreciate it.

Ok. I’m gonna stop working on until I replace the transistor on the top of the hvac box. If I can eliminate one thing the other thing may be easier to fix. I did plug in the high pressure switch because wing no pressure shouldn’t affect it. What two transistor’ did you tell me to jump? I don’t quite follow.

 

[SUBURBAN5]

Did you by any chance see if your doors work/actuators?

 

[Bigred81]

Did you by any chance see if your doors work/actuators?

Yea I checked. When the blower is off I can adjust the doors and hear them working. They stopped working when the compressor stopped working. The compressor works and doors work, until I turn on the blower.