HVAC wiring diagrams please?

Good morning,

The relay is for the rear blower, not the front blower motor.

I attached the wiring diagram for you to view. The front blower module is powered by the dark blue wire from the TIPM. You need to verify power is to the module from the module.

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

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

If there is, then the module is bad. If there is not, then the TIPM is the issue.

Roy

Open hood.
Disconnect and isolate the battery negative cable.
Release the Totally Integrated Power Module (TIPM) cover retaining clips and open the TIPM cover.
Remove the TIPM positive cable retaining nut and remove the cable from the stud.
Depress the four mounting clips to disengage and remove the TIPM housing from its mounting bracket.
Disconnect the wire harness connectors.
Remove the TIPM from the vehicle.

Howdy Roy, where to begin. That is the same wiring schematic that I have but it doesn't seem to be correct for my digital HVAC system. Last thing first, I have ran a fused jumper wire in the TIPM from a fused ignition feed to the dark blue wire feeding the blower resister module and everything works correctly but not with the relay in place. The relay was replaced with 2 known working relays but did not fix my problem.. I actually took the TIPM out and tore it down plate by plate looking for corrosion (scary) but did not see a problem still. I scanned the HVAC system and it told me all the switches in the dash were working correctly, my scanner will actually activate the heater controls one by one to see them working. So i took the heater controls out and traced the wiring there too, they were okay also. The relay in the TIPM if removed has no effect on the operation for the rear HVAC. That relay ( K9 ) is between fuse M36, M13 and M25 in the TIPM it also is where I jumped the dark blue wire from the blower resister control module in the TIPM to a good fused ignition feed. The relay socket has a good ignition feed on 2 legs a good HVAC system (dark blue wire) system going out of it but I don't know where the other 2 wires going out of the relay go to. I have been looking at different schematics for different years hoping for a correct schematic, none of them show a relay feed going to the dark blue wire going the my HVAC system! Right now my system is working correctly but not the way it was built :( . Sorry for being so long with details but it is driving me crazy, lol. As you can see my van in spot K9 actually has a relay for the front HVAC relay so I don't know why I can't find a schematic for this van.
Thank you again frustrated, David W

Got it.

From all your testing, I still think you need the TIPM.

Roy

Thank you Roy. Any idea where I can find a schematic for this system?

Alldata and Mitchel have the same diagrams I sent you.

You could go to the dealer and ask them for one.

Roy

Thank you Roy, sometimes it's hard having a one off car. :(

You are welcome.

Always glad to help.

Roy

I want to replace three zone manual climate control (p55111804) with three zone automatic climate control. They have different wiring harnesses. I need to get the wiring schematics for each unit to line up the correct wires. Do you have them? Do you think it will work?

Three zone automatic is p55111807. I forgot that in original post.

It is not just the harness that is different. You will need to change the BCM programming and the TIPM will need to be changed to enable the controls because the different options use different power and ground circuits.
The automatic system also has extra sensors that you would need to install and a different control module.
If you really want to see what is involved you should get a subscription to Alldata or Mitchell. Those show all the wiring and how it is routed as well as the various parts. From experience repairing both systems you can plan on stripping out the entire dash to get to all the wiring and controls. The rear unit is common to both.

Before I did all that I would find one that has the ATC in it already, with fewer miles.

Thanks for the information Steve. Looks like I will not be doing that upgrade to the car! Not going to get a different car. I have a lifetime factory power-train warranty and the car is in great condition. I plan on keeping it "forever" and was looking to do a few "upgrades" to the interior!

Been there done that. I hate replacing vehicles. I have done a lot to get some where I want them but once you get past about 2005 or so all the technology gets in the way. In some ways it is nice but it all creates a mess when you want to alter it or it starts to fail.

Blower motor will not run. Replace the resistor, heater switch test/replaced.

Hey VMOLMEN,

I have found these wiring diagrams for you to help with the testing. Check the blower fan first then use these guides to continue testing.


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

and

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

Here are some diagrams to help.


Please let us know what you find so it will help others.

Best, Ken