HVAC question

i know about the resistor going bad and not being able to use the 1-2-3 but i have the opposite problem, my 1-2-3 work but my 4 is dead. any ideas???

how is this an HVAC question. elaborate.
Im an HVAC mechanic and i dont know what your talking about.

The fan power in the car I guess? That’s the only HVAC thing with incremental numbers I can think of.

yes, the fan power in the car