Blower motor or switch?

Mercmarquis · #1 (**permalink**) 07-20-2012, 08:49 PM

I have an 09 f350 with regular a/c not the climate control. As of lately I noticed that the blower motor no longer works on the lowest (#1) setting in any position whether heat or a/c. Everything else works as normal just if the fan speed is set to one it no longer blows anything out. I do not hear the fan running either. Has anyone run into this before or has any ideas of things to check? Thanks again!

44magnum · #2 (**permalink**) 07-21-2012, 11:21 AM

Could be the switch but I would bet its the blower motor resistor. To get the lower speeds with the blower motor they use the blower motor resistor, the highest setting will use the full circuit voltage, normally around 12 volts and the slower you get the more resistance is applied and the lower the voltage gets to the blower motor. To be sure you'll need a multimeter.

Mercmarquis · #3 (**permalink**) 07-22-2012, 08:19 AM

Ok I have a multi meter. Where can I find the resistor and what parts of the dash need to come out?

***forddieseldoctor*** · #4 (**permalink**) 07-22-2012, 08:33 AM

You need a resistor. The ones in these truck are electronic and they will drop just one or two speeds when they die.

Mercmarquis · #5 (**permalink**) 07-22-2012, 10:12 AM

Where do I find the resistors in the truck?

44magnum · #6 (**permalink**) 07-22-2012, 10:21 AM

I'm not sure on the exact location but they are usually under the dash on the passengers side near the blower motor itself, Sorry I can't be more exact.

Sent with my mind using ESP.

Mercmarquis · #7 (**permalink**) 07-22-2012, 12:14 PM

Quick google search and found a diagram, very simple behind glove box to right side. Has two bolts on the airbox. I didnt bother to test it but ford dealer will have it tomorrow for 26 bucks. Even if it doesn't fix it I'll have it around, sounds like a common fault. Thanks again guys!

DieselPowerFan · #8 (**permalink**) 01-26-2013, 09:16 AM

Just thought I'd add some pics to this since my Haynes manual (we all know they're not the bible to follow) the dealership and some internet references all say the 6.4 Powerstroke blower motor resistor is on the fire wall in the engine bay!

As stated above those of you looking for this hidden gem, it's tucked way in behind your glove box and is a royal pain to get to!

I found it easiest to remove the glove box fully ( leave it closed and unscrew 4 bolts along bottom edge, then open and gently but firmly push the right side in so the holding tab moves past the edge of the dash), and the side access panel (pops out gently) , and to reach through the side access panel and from below to manipulate my fingers and socket wrench. I also unbolted the electrical pod - when looking at the glove box its tucked into the right and attached directly behind the silver panel of the dash (see pics), I unbolted its two screws and the two screws of the fuel shut off valve, and I even undid the main wire loom that you'll find in there (just one large white plastic "push screw"), all in the name of making room for my hands to work in the confined space.
Believe me you'll have some choice words for the Ford designers who elected this spot to hide the resistor. I'll include some pics, maybe it will help you if you decided to tackle this hassle. I can just see the Stealership smiling at a $35 dollar part and charging 3 hours labour to get it installed!

It only took me about 20 min to install taking my time.