My heater motor only comes on when it wants to. Most often it will come on when it's freezing cold. I always leave it
switched on. If I start the truck in the morning it usually is on, when I stop and re start it usually doesn't work.
Changed the resistor which solved the lw speed problem but now........
The blower motor needs replacement. The brushes are short and when the motor heats up, one or both don't reach the commutator.
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