Why does my AC/heater fan not work all the time?

Heater fan relay gong bad, fan motor itself going out, fan switch intermittent contact, wiring issues. In my area a lot of shops have started turning away vehicles that are no longer shipped to the states due to parts supply, so if you can’t find it on your own then choose a shop carefully.

Answer not posting

I would say it's a problem with the selector/switch , Maybe a blast of electrical cleaner will clean the contacts . A multi tester is useful for fixing electrical problems