a/c guru's in here. Weird problem

[Sleeper]

I can normally figure this shit out, but to me this is a good one.

2008 silverado 1500

On a trip the other day the accumulator turned into a solid block of ice. Got home put some gauges on it and both high and low side look good. Here is the fun part.

When you disconect the low pressure switch on the acumulator. It does NOT turn the clutch off. If you unplug the high side it will dissengauge the clutch.

Put the solis on it and the low pressure switch reads open?

No wires are jacked, relays are good

Im stumped.

[Sleeper]

Or does anyone have a wiring diagram for me

[dee]

Here is the clutch circuit diagram if you need more I'll need to know if it has auto air or manual.

Have you checked the wiring/wires that run to the low pressure switch? Seems strange that the scan tool is showing open though. Those systems usually don't give a lot of problems besides blower motors and resistors.

[Sleeper]

i looked over the wiring and dont see anything, but im going to look it over really good today with more light.

Yeah it was weird to me as well that it had the lp as open on the scan tool. I just wonder if its not in the hvac control modual(the thing in the cabin with all the buttons.)

[Baron Von Crowder]

i looked over the wiring and dont see anything, but im going to look it over really good today with more light.

Yeah it was weird to me as well that it had the lp as open on the scan tool. I just wonder if its not in the hvac control modual(the thing in the cabin with all the buttons.)

its possible, I sell a lot of them, not nessisarily that make/model, but overall.

[Sleeper]

The one thats in the truck is less than 4 months old. Only reason i replaced it was due to worn buttons on the old one when i purchased the truck. I figured id have hvac issues when i noticed that.

Ill swap the old one back in and see what it does.

Edit: I forgot to add the blue wire does have voltage when running and the black has nothing.I dont have a probe to test it with it plugged into the sensor. Was raining and didnt feel like messing with it anymore last night. I have not checked it with the a/c off yet to see if the power is constant. I did swap some relays around just to make sure it wasnt that.

[dee]

What kind of control module did you use?

[Sleeper]

Same one that came out of the truck.

ACDelco 15-74025*

[dee]

I would definitely try the old one to see if the freeze ups stops. It isn't unheard of for a factory part to be bad, it's just less common than parts house brand stuff.

[Sleeper]

Yeah i hear ya. I would have never known if i wouldnt have taken that trip. Most of my driving gets it borderline and the truck gets turned off and it has a chance to thaw.

If you get that wiring diagram shoot it over to me just to have on file.

[Sleeper]

Put in the old hvac control module and all is well. So I just tore them apart and swaped the new buttons I wanted over.

Pos ac delco shit.

[stephen4785]

It's a problem wit the control module. Disconnecting the low ps should disable the comp clutch.

[Sleeper]

It's a problem wit the control module. Disconnecting the low ps should disable the comp clutch.

21 minutes late ;-)

[stephen4785]

21 minutes late ;-)

I fail