Cooling Fan Stuck-On Case Study: '04 Toyota Highlander
The cooling fan on this Toyota stays stuck ON when the car is shut down, draining the battery. Once again the trusty test light saves the day and leads us to one of the most bizarre wiring issues I have come across...
I can say for certain, that no amount of parts-swapping would have fixed this car!!
Enjoy!
This is another great example of how a wiring diagram and a test light "scope-on-a-rope" can pinpoint very obscure problems. A fitting title for this vid could be "Advanced test-light diagnostics".
For a more thorough breakdown of this fan control circuit, check out ScannerDanner's vid:
I apologize for the poor lighting and shaky camera at the end...it was late, I had a cold, and had to finish up the repair :)