Originally Posted by clinebarger
The lower speed resistors are run in series, So if speed #3 resistor was burnt out/Open....You would only have High Speed/4 which bypasses the resistors all together.
*I would first suspect a bad connection at the resistor pack (Melted terminal cavity/Overheated terminal).
*If everything looks good there....Backprobe the Blue/Yellow wire at the resistor pack with a test light hooked to Battery Positive, The test light should light-up if the Switch & #3 speed control circuit is sound.
If you have a Power Probe....Even better, You can see the circuit go from High with the blower switch Off....To Low with the blower switch is in #3 position.
Great stuff
Originally Posted by atikovi
Will see if a pigtail or connector is available.
Yuck!
Glad you found the problem though
Is it still under warranty?