Heater fan know not working - keeps blowing
 

The fan speed knob is not working. Turning does not change fan speed (keeps blowing full blast), pushing off button only turns display off but fan keeps blowing at full tilt.
Any suggestions?
1991 NSX

Even with HVAC module unplugged and removed, the fan keeps running on full.
Suggestions where to start?

Video of HVAC blowing, even when pushing 'off' or using fan speed button.

https://www.dropbox.com/s/38cwf6ebiy...45544.mp4?dl=0

I'm betting these are the same as the rest of the Honda products of the era, and its got a bad blower motor resistor.

I will start there.

Any good DIY links to take the blower resistor out?

@KraftwerkTurbo , this is a classic symptom of the climate control board going bad because of old solder. Contact Brian K at Acura NSX electronics repair to get it repaired.

PS, welcome to AZ!

CCU was send in for repair (by previous owner to Auto Tech Rescue)
Blower HI relay NOT stuck.
ONLY pulling the Power Transistor turn fan off.

Previous owner had cut the old transistor but left in housing. zip tied new transistor in. Appears transistor housing touching metal (here: alu coolant/ac pipes?) creates a short.

Removed old transistor (what a PITA that is; could not get heater hose off, rear screws is a killer). Put new transistor (ouch! $$$) in. Running now.

Have 'brother' car (this one manual, other is auto) with similar issues. Will first test relay and transistor. Then will contact above mentioned Brian for quote; seems he is resident NSX climate control guru?