AC/Heater fan won't work correctly at highest setting

[jeffc]

92 NT 1.8

My AC/Heater fan works correctly in all settings except for #4 (high). When I set it there, sometimes it will come on and work for a few moments, then stop. Changing it bakc to position 3 (or any other position) and it will work correctly. Change it back to #4, and it may or may not work correctly again for a few more moments. Doesnt seem to be affected by inside or outside temp, or position of my gas pedal/rpm range.

Is it as simple as the electric motor starting to go bad? It makes no odd noises either...

 

[Defiant]

Probably the resistor pack:

http://www.dsmtuners.com/forums/showthread.php?t=145931

http://www.dsmtuners.com/forums/showthread.php?t=97686

 

[el aguila]

I haven't looked at the wiring diagram for this, but it could be the blower motor resistor block or the high speed relay (if it uses one).

 

[jeffc]

That seems to be me. Thanks for the info. Am I going to be able to get to this by playing gymnast under my dashboard, or will I have to disassemble it?

Probably the resistor pack:

http://www.dsmtuners.com/forums/showthread.php?t=145931

http://www.dsmtuners.com/forums/showthread.php?t=97686