2004 Yukon XL A/C Compressor not turning on

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zachreilly0

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Hi, my 2004 Yukon XL compressor relay needs to be jumped in order for the compressor to kick on. I have changed the compressor, low pressure switch, clutch cycling switch, and the climate control module. I have codes B0408, B0229, and B0414. I really don't know too much about A/C systems so If someone could help me out here I would appreciate it. I've heard it could be the HVAC control panel or I have two bad actuators, but I'm not too sure. Thanks
 

Matthew Jeschke

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Bad relay? What do you mean by jumped exactly, your shorting the relay switch?

Have you checked the coil side of the circuit? How's your chassis grounds there front driver side. The under hood junction box / relay coil is grounded somewhere to one of those. Otherwise, there's a control line you can trace that back to the switch in the truck. Do you need wiring diagrams?
 

Mudsport96

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Are you getting 12vdc to the connector at the compressor? Start there with a volt meter. If you are, then it is a compressor issue. If you aren't then you have to figure out why not.
 
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zachreilly0

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Bad relay? What do you mean by jumped exactly, your shorting the relay switch?

Have you checked the coil side of the circuit? How's your chassis grounds there front driver side. The under hood junction box / relay coil is grounded somewhere to one of those. Otherwise, there's a control line you can trace that back to the switch in the truck. Do you need wiring diagrams?
Can you send me wiring diagrams if you have them?

Thanks
 

nonickatall

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If you can bypass the compressor relay and the compressor starts, then it is most likely that your refrigerant level is not right.

Of course it could also be that the compressor relay is defective. You can simply measure on the control cable whether 12 volts are arriving at the compressor relay when you switch on the air conditioning.

Then it is the relay.

If 12 volts don't arrive there, then your system won't activate the compressor. This is usually the case when the pressure switches on the low pressure and high pressure sides report that something is wrong.

And that is when there is either too much pressure in the system or too little. And the reason for this is usually an incorrect refrigerant level.
 

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