...on my 1997 Explorer ... the motor was OK when I tested it so all I had to do was stick a new blend door up into its slot...
I've heard about blend doors failing on really old models. But, the actuator itself is more typically at fault. Either the internal gears strip or the carbon traces wear out. The older designs had weak gears. To save money, they left out limit switches (which would have made the actuators reliable for the life of the vehicle). Instead, they programmed the damned things to "test" the limits from time to time which causes the gears to strip. I'm told this happens every so many ignition cycles.
After years of owners enduring this, Ford redesigned the units to have more robust gears. BUT, they still never installed limit switches! And, the upgraded gears don't help because now the newer units typically fail from crappy carbon traces (cheaply produced). These wear out as pickup wipers inside the unit repeatedly sweep from cold to hot and back again over time.
It all comes down to corner cutting and penny pinching -- in a $50 part that costs $1000 or more in labor to get at and replace. And, don't forget our trucks can have as many as THREE of these things installed.
Is anyone reading this an attorney?????????
