Tahoe AC problem

[j cAT]

Originally Posted by benhiers

I put power to the hot side of the hpco switch and the clutch did pull in.the problem is Im not getting power to the hot side of the hpco switch

this high press cutout switch does not have 12volts to it . this is a signal that goes from the hvac control module to the switch then to the PCM input. if the switch has high pressure it opens. then the PCM prevents the ac clutch from getting power. the pcm monitors many other componets when out of range this will prevent ac clutch from actuating.. short out this switch. then using a ohm meter with the ac running monitor the switch resistance it should be zero ohms.if not then it is bad or the pressure is too high. measure the high side pressure.

[brcidd]

Originally Posted by j cAT

.. short out this switch. .

I would never "short out a switch" jumping the signal to ground may damage your PCM.

The thing to do is to "jumper" the electrical connector that attaches to that switch- most use a paper clip or a fused jumper line. Do not allow the paper clip to touch any metal or to "short" out.

The term "short" usually refers to a 12v hot signal being introduced to a body ground. Let's not confuse the original poster.

[j cAT]

Originally Posted by brcidd

I would never "short out a switch" jumping the signal to ground may damage your PCM.

The thing to do is to "jumper" the electrical connector that attaches to that switch- most use a paper clip or a fused jumper line. Do not allow the paper clip to touch any metal or to "short" out.

The term "short" usually refers to a 12v hot signal being introduced to a body ground. Let's not confuse the original poster.

I did not correctly state this. It should be short out the connector that goes to this switch should be shorted out. then with the ac running measure the switch resistance.

shorting out or bypassing this switch , is what I was hoping to help with on finding this problem ...,

grounding out a circuit is not what I stated or indicated.

[benhiers]

I knew what he was saying.I have jumped the connector at the high pressure switch.ac clutch didn't kick in.but tonight I will get ac clutch kicked in and measure resistance at high pressure switch.

[j cAT]

Originally Posted by benhiers

I knew what he was saying.I have jumped the connector at the high pressure switch.ac clutch didn't kick in.but tonight I will get ac clutch kicked in and measure resistance at high pressure switch.

the hvac control module is most likely the problem ..with all the testing you did , the results I have read , and this looks more like this is the problem. many have had this occur at this time,with this model year.

[benhiers]

got a hvac control panel from a junkyard,and it fixed the problem,thanks for all the help guys

[j cAT]

Originally Posted by benhiers

got a hvac control panel from a junkyard,and it fixed the problem,thanks for all the help guys

thanks for the report . this will aid others .