Girlfriend has an 03 Accord, 198K miles, Last week I noticed driving it,
it seemed the blower motor speed did not change. It would
however, turn off. Yesterday I did the Oil Change, prior to that
the car did not start, (either bad battery in the cold or something
was left on). After that, now blower motor only is in HIGH and
only STOPS with key off. Full disclosure, it does have an aftermarket
control panel, the factory radio died and girlfriend was sold this “kit”

Any thoughts?
Bill


(see attachment for the control panel she has,
photo is from the web, not her stereo)

 

Tough call with the aftermarket unit. However the blower resistor testing is where I would start...usually when it goes bad you get "high" and off or nothing so it doesn't seem that might be the issue but worth testing anyway.....at least if I wrong you will know the issue is "before" the resistor/blower motor.

 

Here is test for power transistor.

good luck