Need help! blower fan not working

There's also a relay, HTR, in the driver's side cabin fuse box. I hope it is that, because the next possibility is the A/C amplifier.

 

It sounds like you have a wiring harness problem. Maybe a wiring harness connection developed a bad connection, heated up and finally failed.

I suggest you obtain the electrical wiring diagram for your model year at techinfo.toyota.com so that you can follow the flow of 12V current with a digital multimeter, and figure out where it no longer is present.

 

Do you have a good ground? Should be 0.1-0.2 Ohms, measuring the connection at the blower motor controller wire harness to the chassis. There has also been some discussion of problems between the MFD and Gateway ECU sending the command to the A/C amplifier.

 

I've posted the portion of the service manual that deals with this. I don't understand what "nothing its (sic) showing up" means. Does that mean that none of the three pins of the wiring harness showed low resistance to chassis ground?

 

I have an 05, and it's doing the same thing. Sometimes, my blower motor works, and sometimes it doesn't. Now, I can't get it to come on at all. Which brought me to this thread.

When you figure it out, please post your fix. Thanks.

 

I went ahead and took the proactive route, and took the car to the dealer and had them install a new fan motor. That fixed my issue.

 

This is a notorious problem and an easy DIY job. My blower fan (2008 Prius) started going bad about a year ago, I would have to kick under the glove compartment to jumpstart it. I bought a replacement fan online for $50 - removing the old one and installing the new took 30 min. Before installing the new one I compared the two fans, powering them with my workbench power supply. The old one required a lot of amperage to get turning, or I had to physically spin it with my hand to jumpstart it. The new fan started right up with low amperage, this proves that these fans wear out over time or the motor brushes get dirty.

Tools: 1 phillips screwdriver, 1 size 20 star driver (or use small flat head)
To take out the old fan remove the glove compartment to reveal the white plastic fan housing and filters (while your at it clean or replace the filters). Then remove the kick plate down by the floor mat (it snaps out). behind the kick plate there is a metal transmission control unit held by 2 philips screws to the fan housing, remove this. Then remove the entire bottom plastic plate of the fan housing, it is attached by 5 phillips screws. After removing the screws you have to kind of wiggle the plate out of there. with the plate gone you have access to the blower motor, it is attached by 3 star head screws, remove them and pull the fan out and unplug its wire harness. That's it, just install the new blower fan and put back together. works like new.

Here's some photos of the job:

 

Do you have a part number for the fan? My blower motor in my 2008Prius is squeaking and needs to be replaced too. Thanx.

 

Just pull it out, clean it, lube it with some 3 in one oil. Reassemble. That should take care of the squeek!

 

My 06 Prius blower motor will not not start sometimes. The problem is somewhere in the blower motor starting circuit. I can start it manually by removing the cabin filter, reaching my fingers down inside and giving the fan blades a spin. The motor will then run until I shut off the ignition.
I will pull the motor out for repair or replacement in the spring or sooner if it quits completely.
Does anyone have knowledge of those starting circuits?

 

There is no "starting circuit". The fan motor is just a DC motor. The problem is that due to age, the motor no longer produces sufficient starting torque to get the fan spinning.

You might try removing the existing fan to see if you can clean it up and get the motor to reliably spin up. If not then just replace it.

 

It's due to brush wear, as it is a commutator type motor. If you are the sort of DIY that can take it apart and clean the commutator and replace the brushes, it will work well again.

If not, then go ahead and replace.

 

Figured this must be my problem (blower gone bad) after reading this last night. I had noticed it was delayed in starting up a very few times over the past few weeks or months. Then, yesterday it wouldn't start at all. I followed your cue here last night and removed the glove box and banged on it. Started right up then and is still working! I've ordered a new $52 blower off of eBay and will install as soon as it arrives. Mine only has nearly 195K miles on it!

 

New blower arrived this afternoon. Socked it in, replaced all the panels, and had all my tools picked up in about 45 minutes. Good for another 195K miles. Thanks to all who posted before me. Helped me realize what I needed to do!

Too bad the hail storm last weekend trashed the car. Damage estimated at nearly $2,800. I have two other vehicles which suffered almost as bad, but I haven't had them estimated yet. Sorry, I know that's off topic, but I had to whine a little.

 

Followed this post and fixed my AC with a new blower from Pep Boys. $83 and about 45 minutes from start to finish

 

Mine is starting to act up. Will disassemble over the next couple of weeks.