I have an 2007 N14 Hatch back with automatic temp. control with no blower. I replaced the final stage regulator, no help.
If I power up the blower motor with an jumper directly to the motor it runs.
If I power up the car with the blower motor not plugged in, the control panel will light up as normal and you can make changes to temp & fan speed then plug the motor in it will run. You can then make changes to temp & fan speeds, the motor will respond to all.
shut the power off and then re power the car car up again, no blower but the control panel will come up on line with no blower and will not respond to changes. Unplug the fan motor and power up the car, plug the blower motor again, blower motor will run and respond to control changes.
Ground or resistor issue? Is there another resistor other than the final stage regulator, If so where is it,
and how do I get to it?
Thanks
Gary

 

Found the problem, it was an loose wire on the final stage regulator. Likely became loose when the new regulator was installed. the ground wire didn't push on enough with the other 3 wires that made contact.