Blower won't go to defrost

usually the vent doors get stuck, but the actuators can be bad as well. it's a big job, most of the dash has to come out

 

I have a similar problem on my 2008 Prius. All of the output vents work except for the windshield defroster. Haven't tried the defroster since last winter. I'm the original owner, and there has been nothing occur that would seem to have caused this. I've read in other posts about the "air actuator" under the dash and just above the accelerator pedal. Looking at an online parts dealer, they call it the "Heater Blend Door Actuator". I've read that it is hard to reach the upper screw to replace it. The only other possibility would be that a louver or deflector was stuck or broken somewhere up in the dash, and that's a really difficult fix because the dash has to come off.

The question is this: is it most likely the Heater Blend Door Actuator that is the problem?

 

There are three door mechanisms that are in there, and so there are three actuators. Somebody posted the relevant parts diagram page here not long ago, let me see if I can find that. (Search search search ... copy copy ... paste paste ...)



The actuators are the parts called out here as 87106 H, J, and N. The N one controls the door that selects air intake, fresh or recirculated. Good luck ever getting to that one if you need to, squished in there between the heater and blower cabinets.

The other two, H and J, are not so hard to get to, if you can get yourself upside down in the driver's seat. Each one is only held on by three screws, but there is cramped access to some of the screws. A very flat offset screwdriver was suggested by yitznewton for that.

One of those controls the air temperature, by blending air that goes through the heat core with air that goes past it. When people say the "blend door actuator", that's the one they mean. The other one selects the air outlets: feet, face, defrost. I forget which of those is H and which is J.

Because of where those are located, it is not too hard to stick your head down there and watch what they do while your accomplice changes the outlet settings (for the outlet actuator) or the temperature settings (for the blend actuator). Then you'll be pretty sure which is which.

The actuators can get flaky, which is not a big job, at least for either of those two on the easy-to-reach side. Sometimes the actuator is ok, but the door itself is somehow broken or jammed inside the heater case. That's a big job.

 

Thank you, ChapmanF! I've seen your ID on some very useful posts. I see wiring harnesses running to the actuators. Have you ever heard of it being a wiring problem? Maybe start by disconnecting, inspecting, and reconnecting?

 

Spotted this video which addresses the three "actuators" pretty nicely.

I'm pretty sure the easiest to reach one is the outlet selection ("blend door").

 

Please don't call the outlet selection the blend door.

The blend door is the one that blends heated with non-heated air to get the temperature you want.

The outlet door selects the outlets. The intake door selects the fresh or recirculated intake.

Those are the three.

As for the wiring harnesses, starting with Gen 3 Prius, the wire harness is actually 'smart' (if you're curious, you can read this post for more about that). Plus, in Gen 3, the servos themselves are much more reliable (they use digital position encoders rather than the old potentiometers that could get flaky). If you had a Gen 3, you might have to wonder about the wire harness before the servos.

With a Gen 2, the wire harness is very simple, and the servos use potentiometers and are prone to misbehaving over time, so that is the likely problem.

 

Anyone that have got out the blend door?
The one above the outletdoor?

any tips?

im starting to wonder if i can move other stuff, to get more space?

i saw a video of a right hand steering car, that seams much easier, but mine is lefthand drivning.

 

Hi Clas,
I have the same problem...it is the upper actuator that is malfunctioning.
My plan is to remove the lower one to gain access, and then try to get the upper one out.
I just ordered some low profile screwdrivers, so hope to tackle it next weekend.
I will let you know how it goes, or if I find any other tips on the web.

 

hi i actually got it out today.
I took it out from the top, but the screw on the lower side i took from the floor.
No special tools, but the last screw took me at least 1hour..(whitout special Tool)

to remove the dashboard was easy, took me maybe 30min, with some Google..

but i have a new problem, my ”tracks” in the acurator is bad.. What should i Do now?

 

Hello folks!
Welcome me to the malfunctioned actuators club. Just localized an issue I described in this post - this is an outlet selection actuator, the one which is behind blend door actuator, so it's harder to get it detached. See the video I recorded - I change different outlet modes and this "farther" actuator is doing its job - sometimes (randomly) it stops properly, sometimes it can't stop and producing these annoying "clicks":

So my question to Clas:

Is that obligatory to remove dashboard to access this "farther" actuator?

 

The post in the following thread
how to replace bad air vent servo | PriusChat
suggests you can get to it by removing only the dash panels surrounding the steering wheel.

I am finally going to try to do that method this weekend. I ended up buying a used servo off eBay for $15 in advance, so I can just swap it out rather than trying to fix the old one or leave the dash disassembled while I wait for a part.
I will post my experience here.

 

Oh, good luck! Please keep us posted and take many photos Just do doublecheck - do you mean this part? (the drawing looks wrong there but maybe you can confirm the partnumber)

 

Whoa, yikes!

Ok, now we know a reason not to wait too long if you have been hearing an actuator get 'fidgety' down there. Mostly we've been treating it as sort of benign annoyance ... "yeah, eventually when it annoys you enough, take out the actuator and clean the traces".

That right there is clearly an actuator that got fidgety a long time ago, and in each of its discrete outlet-selected positions there, it has spent so much time fidgeting slightly back and forth that the contacts have worn through the traces. (If we knew how the mechanical linkage translates the rotary position into outlet positions, we'd be able to tell which outlet settings you use the most)!

At this point I would just buy an actuator. So it's $200, or maybe $140 at the right dealer. That would have been Toyota's solution all along. Disassembling your own can save you that coin if you get to it soon enough, but in this case it didn't work out. You've already invested the labor in dash disassembly and all, so I would just bite the bullet, drop in a nice new one, and consider it a job well done.

Maybe ... clean the other two, while you have the dash off ....

Note (this came up in an earlier thread as well), that part link above is labeled "inlet door actuator" if you follow it, which is the wrong name, but it is linked to the right part on the drawing. So is it the right number or not? I don't know, but it's the kind of thing where you could probably point that out to the person at your dealer's parts counter and get them to help figure it out. Or bring your old one with you and compare before you bring the new one home.

 

On a normally functioning car, with the servo installed and the car off, is it possible to rotate that white plastic wheel by hand? Or does the servo lock it in place somehow even when it is off? The question being, if the inside of the evaporator has a jammed/stuck door, can that be determined without first removing the servo.

 

From that other thread:

Today I took off all the panels around the steering wheel - and it didn't help in any significant way. There was no path through the top or lower panel to view the upper servo (well, maybe a tiny corner of it). I am about as skinny as an adult can be and there was no way I was going to get a hand to those devices through the areas cleared by removing the upper panel. Removing the "white plastics" for leg ventilation might help, but the post did not say how to do it. Probably taking off those panels helps with that. It would also let a bit of light in, because otherwise it is really dark under there. The main problem is the ECU right next to the mix servo, which blocks everything. Does anybody know which ECU that is so I can look it up in the manual?

I also learned...

The hood release lever on this car is partially busted. There is a plastic peg the spring sits on and it only extends part way into the spring. Dash disassembly says to "remove it" from the lower panel, but even after the white plastic part was released from the panel the handle would not slide through the hole, it was too big. Did they mean release the metal cable from the lever?

I could not release the "P" switch. Poked all over it and could not find a release lever which would move. There were two depressed areas which might have been the release, but pushing on them with a small screwdriver didn't release the plug.

The nut on the negative battery cable faces the rear of the car and it was really hard to access with a typical size wrench since the handle was mostly blocked by the plastic around the inside of the trunk. Luckily I had a little tiny wrench which fit in there.

 

Well, the motor in there has a worm gear that then spins a couple stages of reduction gears. I won't say anything "locks" it in place, but that kind of mechanism can be really stiff to try to rotate from the gozouta.

You would probably learn more by (I hear you groaning) removing it.

I have a vague memory that, with one of my Prii, I did that exactly once, then took the bolt out of the clamp and put it back through the other way.

 

Success!

Remove vents and dash panels surrounding steering wheel.
Here is a good video that shows removal of the entire dash, but just need first 1:30.

The upper actuator is directly behind the shift lever. I removed the shift lever (2 bolts on top, 1 one bottom). This does not give you access to remove the screw, but it does provide a sight line to the upper screw which was very helpful. (photo3)

Remove white section of ventilation duct. There is a plastic push connector and tabs front and back. I had some trouble getting this off and not exactly sure what I did to make it come out finally. (photo1 and photo6)

Remove nuts holding the computer unit to the left of the actuators. Two screws at the bottom, one way up at the top. I had to use two long extensions with a universal joint at the top (photo4). I did not detach any of the cable harnesses, but taking the nuts off allowed me to move it to the side and gain some extra hand-room. (photo1, photo2 and photo4)

Remove the lower actuator.

To remove the upper actuator I used a long screw bit from my drill-driver and turned it with a small box wrench. Photo5 shows the set-up used. For the screws on both actuators I ended up using various combinations of screw bits and sockets, depending on how much clearance there was. Getting the linkage off was difficult, I ended up just breaking one since I had an extra from the used part I bought. (photo3, photo5)

Taking everything out took about 3 hours, about 1.5 hours to put everything back. And it works!

 

Congrats! I have to go the same way.
Could you please share more details about the part you bought? Partnumber, and maybe direct link also? There is lots of confusion about how this actuator named and illustrated on Toyota's official resources like this one
8710647090 - Hvac air inlet door actuator. Servo, damper (for mode) - Genuine Toyota Part


Thanks!

 

In the full diagram on that page the part is numbered 87106J.

Here is a link to the Prius AC service manual
https://attachments.priuschat.com/attachment-files/2018/06/147172_AC.pdf
If you go to pages AC 145 and AC 151, you will see that they are described as follows
"Air Outlet Damper Servo Motor" (upper one...location of air flow into cabin)
"Air Mix Control Servo Motor" (lower one...temperature)

I attached some additional photos that show the two units side-by-side. They have white numbers printed on them, but neither corresponds to the 87160J in your parts diagram? I note that the number in black stamped into the plastic is actually the same (PP-GF20+M20). So they are perhaps the same part? Also the upper outlet control has shorter linkage arm that extends only in one direction. The lower temperature mix control has longer linkage arm that extends in two directions.

I bought mine on used on eBay, so just used visual verification to pick the right part, which was easy since the linkage was still attached. You might want to check with the dealer to see if the unit comes with any of the linkage or not.

Good luck.