Chosen Solution
I drive a 2002 Nissan Quest. The blower motor will only work on the highest setting because the blower motor resistor keeps breaking. I changed the blower motor resistor about 7 times. Settings 1, 2, & 3 will work with a new resistor but not for long. Most recently, I also replaced the blower motor itself, along with a new resistor. The resistor still blew out with the new motor. I am not sure what could be causing the resistor to constantly blow out.
@theartistq that is a tricky one. If your blower motor resistor continue to fail you do want to do a few things. First check the amperage that the new motor pulls. If it is to high then there are issues with that. After that you do want to check for corrosion on the wiring and connectors since that can cause heat which may cause failure. Next is to check the airflow to ensure that it is unobstructed. Leafs, mechanical obstruction, water as well as other debris can cause overheating/shortening out of the resistor. you also need to consider the fan speed selector switch. Make sure that it is not the switch that shortens it out. Check for anything unusual at this time.
Pretty lame answer. All true but the root cause is improper and inadequate design engineering work. Not doing a FMEA failure mode effects analysis with a multidisciplinary team with design, manufacturing, product quality, supplier quality engineers in the cross-functional team chartered by the chief product engineer. I might further add as this could be a fire hazard a complete SHA safety hazards analysis should have been performed for this component. Both of these happening are the direct responsibility of the Chief engineer on the project. If all of this fails it’s kicked to service engineering where they chartered to develop a fix or work around. This may or may not include issuing a service bulletin or a recall. Could be mandated or voluntary. Key is having the resister,fan switch,fan motor,fan and wiring harness manufacturers work in a systems approach together early on. This is when you have the best opportunity to obtain the best quality, reliability and the sweet spot for reducing costs and obtaining the maximum TCO.
