Help with heater blower

[bdmorgan72]

Hi all. New to the forums, having some trouble with my daughter's 2007 Yaris. Blower stopped working a few months back, but would occasionally come on when traveling at high speeds, or when manually nudging the fan with glove box removed. All signs pointed to faulty blower resistor. Ordered on at local parts store and replaced last night. While parked, everything seemed to work great, all 4 speeds. But as my daughter pulled away, she called to say it's not working again. No fan at all in any position.

Any thoughts on what I might need to try next? Why would it work when parked, then fail again immediately after driving off? Seems like the motor itself is working, as it had plenty of power during my tests when parked.

[bdmorgan72]

Update: My daughter says the fan is actually intermittent and only blows on slow speed, no matter what the dial is set on. It will come on / turn off randomly. She reports that it's at least working with more frequency than before I replaced the resistor, but obviously still not working correctly.