HVAC (heater AC) wiring diagrams please?

Good morning,

I attached a wiring diagram for you for the A/C system. Check the fuses for power on both sides.

https://www.2carpros.com/articles/how-to-check-wiring

and

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

You need to test pressures as well. You need at least 25 pounds for the system to turn on.

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

and

https://www.2carpros.com/articles/how-to-check-wiring

Check out the diagrams (Below). Let us know what happens and please upload pictures or videos of the problem.

It sounds like the blower control module is out but to be sure this guide can help you check the power and ground and I have included the air conditioner and heater wiring diagrams below.

https://www.2carpros.com/articles/blower-fan-motor-works-on-high-speed-only

and

https://www.2carpros.com/articles/how-to-check-wiring

Check out the diagrams (Below). Let us know what happens and please upload pictures or videos of the problem.

I attached three pics below for an 2008. Let me know if they help. Also, let me know if there is something you can't see/read because of size.

https://www.2carpros.com/articles/how-to-check-wiring

If you look below, I reattached the schematics. I cut the pics in half to make them more readable, but I did overlap them so you can follow from one to the next.
I hope this helps.

Take care,

Joe

Hello,

I have found the wiring diagrams (below) for you so you can do some testing. Here is a guide that will help you check for power and ground triggers to see where the failure is happening.

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Please run some tests and get back to us so we can continue helping you.

Cheers, Ken

The system may need to be calibrated which is done by removing the HVAC fuse. Here is the wiring diagrams for the climate control so you can see how the system works and to check the connections before changing out the control head:

https://www.2carpros.com/articles/how-to-check-wiring

Check out the diagrams (below). Please let us know what you find. We are interested to see what it is.

Pull HVAC fuse inside truck with key on for sixty seconds it may reset actuator. May also be a bad relay connection. Then see if actuator is getting power or not. One other thing if this truck blower quits while driving it may have the harness burnt up. Here are the air conditioner wiring diagrams so you can see how the system works.

Which wire did you apply the 12 volts too? If you take a look at the wiring diagram below you will see that there are control wires for each actuator, low ref (ground return), 5 volt supply coming from the module.

If you applied 12 volts to one of them then all that did was send the actuator to one side or the other. The way that works is, if there is low voltage on one side the door swings one way and then it applies it to the other side to get the door to swing the other way.

So even if you left it this way, the blend door would not change from that full position and it would blow hot air. You need the control module to be able to vary this voltage so that the door can move and change the temp.

Let me know which wire you did this too and then I would suggest removing the 12 volts and let's check to see what the voltage is on each of these at both the actuator and the module. That will tell us if the module is even sending the correct voltage.

https://www.2carpros.com/articles/how-to-check-wiring

Does that make sense?

You will need to use several parts from the 2002 truck. I have attached the entire wiring schematic for you. I had to break the schematics into sections to make them readable. The first two are specific to the compressor function.

___________________________________________

I hope this helps.

Take care,
Joe

Here ae the HVAC wiring diagrams you are looking for and a guide to help check the connections:

https://www.2carpros.com/articles/how-to-check-wiring

Check out the diagrams (below). Please let us know if you need anything else to get the problem fixed.

Hi,

I attached two wiring schematics below. The third pic I enlarged. It is specific to the control module. Take a look through them and let me know if that is what you needed.

Take care,
Joe