My quest is a 2008 model .controls in front and back for the air and heat .the front blower motor is stuck on high.the rear one still adjusts just fine.but on the front ,when you turn the control to off you can hear it closes and it starts blowing out at your feet still on high.i replaced the blower motor resistor with no change.i was gonna check out the actual blower motor with a voltemeter to see if there was a voltage change in the wires going to it when the speed is changed on the controls but I can't find it.im guessing it's hiden in the box in the center I don't know .im really wondering if I got a bad resistor but I bought it online from rock auto so it's a pain to replace it .is there a way to test it with a voltemeter or does anyone know anything else to check?

Google and download the FSM first, then give it a read and look for a power transistor which controls the blower motor. I am sure yours is shorted.

So the power transistor is a different device than the blower motor control module/resistor? That's what I replaced with no difference. I googled the power transistor and didn't really come up with much

Download the 'ATC' section of the '08 Quest service manual and around ATC-78. Dunno what you bought for a part there but that one does not use a resistor, rather, a 'variable blower control' unit, which changes the blower speeds by use of a PWM % duty cycle.

far raf wrote: ↑

Fri Oct 12, 2018 9:52 am

Google and download the FSM

No need to Google it, just click on "SERVICE MANUALS" here on Nicoclub

That is what I changed with no difference.apparently it's got a lot of different names

The term I gave is what Nissan calls it.

The control signal that unit gets likely comes from something else, the service manual section I pointed out has detail testing on it. The PWM you will likely not be able to read, it requires specialty tools. The result is simple enough though, the blower speeds up and slows down based on it.