I have a 2013 Ford Flex my issue is my blower motor always running on high when the engine is on when the engine is off the blower motor does not run I have changed the blower motor resistor and I have to change the wiring harness and I have changed the relay so I don't know what the problem is I need help
I have to change the wiring harness
Why do you have to change the wiring harness?
Since the blower motor is computer controlled you would likely require a fancy bidirectional scan tool for diagnosis.
@chucktobias I changed the pigtail it was bad
@chucktobias now could it be the HVAC control modular
@deadman16785 You would need a fancy bidirectional scan tool to determine that. (Command the HVAC module to vary the fan speed and see if it responds.)
These computer-controlled systems do not lend themselves to easy DIY solutions to problems. Certainly throwing parts at the problem is the wrong approach and is unlikely to do anything more than make your wallet lighter.
@chucktobias what else could it be I've changed every other component except the blower motor itself
@deadman16785 That is what's known as the "parts cannon" approach, blindly changing parts hoping to fix the problem. In the vast majority of cases simply replacing parts without doing a proper diagnosis doesn't yield a good result.
There could be wiring faults, bad grounds, software issue requiring an update, even faulty new parts (all too common today).
Failed components can also cause problems in unrelated systems by interfering with data transmission. South Main Auto even had a case where a rear camera rendered a vehicle undriveable due to its generating garbage on the data bus.