Hi,
Thanks for your question.
I attached the testing when the fan are inoperative. Basically, it has you run through your wiring but if you have a scan tool that can activate your fans for testing, that will be the easiest way to prove out wiring.
However, if you don't have a scan tool, please refer to the wiring diagram. You will need to make sure you have power at the fans themselves.
Keep in mind the ECM is responsible for grounding the two speed relays and the control relay. If you look at the diagram, it reads left to right. Power comes in on Fuse F11U and supplies power to the low speed relay. When the ECM wants to turn the fan on it grounds the control relay which grounds the low speed relay circuit, the relay closes which sends the power to the Right fan motor. Then when the ECM wants to turn the high speed fan on, it grounds the other relay.
If you have voltage coming out of the fuses, and your wiring checks out, then most likely your ECM is the issue.
Please let me know if you need more help going through this test or let me know you results and I can help decide if it is truly the ECM. Thanks
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Saturday, May 18th, 2019 AT 11:59 AM