Blower turns off on #5 setting

[justsumday2010]

Hello my wife has a 2001 pontiac montana and I know the A/C don't work at all but the heater works. My prob is when I turn the fan speed to 5 on the nob it turns off and when I turn it to 4 it turns back on so 1-4 works great and fine but turns off at 5 what would be making this happin? Thanks

 

[EaOutlaw]

Most likely is just a defective Blower motor resistor http://www.napaonline.com/Catalog/C...Blower-Motor-Resistor/_/R-ECHBR100_0239908248

I am not sure where it is located on your vehicle but it will be mounted on the heater ac case where the blower motor will cool it off so it should be down stream of the blower motor look at the picture provided that should show you what your looking for, my guess would be behind the glove box, in that general area.

here is a video I found that shows how to do it and where it is. https://youtu.be/VugkJmnFLJM

I will ad this would be a good time to replace your cabin filter and inspect for leaves and debris in the case, use a cell phone camera to take a video of what it looks like down stream of the blower motor.

 

[justsumday2010]

Most likely is just a defective Blower motor resistor http://www.napaonline.com/Catalog/C...Blower-Motor-Resistor/_/R-ECHBR100_0239908248

Ok is There anything else I could look in to?

 

[sergeimoskva]

Hello !
The fan is in position 5 on the switch depends on the switch. (See diagram)

This relay is in the block of resistors. (see picture)

Probably not working relay. This relay can not be repaired. (See picture)

Only the replacement of the unit completely (see picture)

Good luck to you!

______________________________

 

[justsumday2010]

Thanks for the tip I'll look in to that

 

[EaOutlaw]

Ok is There anything else I could look in to?

I did not notice your second question till just now,

It still sounds like a defective blower motor resistor assembly, the one I found is like 40 bucks or so.

To determine for sure what is wrong you will need a computer safe test light or a Digital volt ohm meter. you would need to test the incoming signal from the blower motor switch to insure the switch is sending the signal to operate the fan on the fan speed setting of 5.

Short of doing this with the provided wiring diagram from our friend sergeimoskva you will have to buy the resistor assembly and install it.

once the fan operates on speed 5 you will want to insure the cabin filter is new or at least clean, and run a amperage test on the blower motor if the motor is drawing too much amperage it could burn up the resistor again.

same thing with a clogged cabin filter this will reduce the air flow causing the resistor to go bad prematurely.