The tack will drop to 300 to 400 rpm, almost stall then its fine. The colder it is the more or longer it does it. When the weather is warmer it will quit after awhile and in summer time it runs fine. The heater ac motor has a ticking noise when on and of course ticks faster has you turn it higher. I would like to change that also, but it seems to stall faster if its on but in hot weather with ac on there is no problem. How can I stop the stalling and how do I change that blower motor, I tried but cant get at some of the bolts. Is there a easier way?