surprise surprise ...
I was watching tv in car while parked. As you know tv goes off after some time while it's powered by battery.

When I restarted the car, all of sudden blower came back to life after 6 months.

Not sure if any sensor got reset by itself while it was shut down by battery cut-off. As this is the only unusual activity I did in last six months.

I'll be curious to try again in case blower fails once again.