I have a 2007 Camry LE. It's been a really good car.

Last Friday, all was fine, I even used the air conditioner, although the weather here is cooling down quickly. Everything worked just fine this day.

The next morning I got in the car, flipped on the air conditioner, and got nothing but straight HOT air blowing out of the vents. A look under the hood shows the ac compressor engaged and the line is cold to the touch. It got so hot inside the car that I had to roll down the windows for relief.

It's acting weird, since then I may or may not be able to turn the heat off. It's as if the control panel or brain control thing has gone whacky.

The car does NOT have the fancy climate control where you set a temp and it maintains it. It has the normal old fashioned type of controls: a knob to turn by hand for the air blower speed, another knob to move to select between air, heat, vent, defrost, etc, and another knob to turn to vary the heat from cold to hot.

I notice now that when I start the engine, the light that indicates the rear defroster is on is now blinking at a steady rate for maybe 20 seconds or so, it does not appear to be flashing a code number as far as I can tell.

Today again I tried to select the air conditioner for a few minutes, got HOT air blowing out the vents. I was able to turn it off (the other day no matter what I did I could not stop the HEAT from coming out of the vents.

It's as if there is a weird control issue. The control unit may be electronic, I don't know, as the car does NOT have the fancy automatic climate controls "set it and forget it" type.

And to clarify, when I say it blew out HOT HEAT, it was the same HOT that you normally get out of the heater vents when desired.

It has really cooled off now, so I probably won't need the AC until spring, but I'd really like to be able to control the HEAT output.

A Google and youtube search didn't tell me much. I've called my really good independent garage about it, and I can take it in on Wednesday, but I'd like to see if anyone has had this happen and what it took to fix it. If I can do it myself with a few ideas, that'd be great, otherwise it goes to the auto shop.

Thanks in advance, Gene.

I'll take a stab at it.

Blowing hot air sometimes means you need to charge up the AC. At least I hope that is the issue. Your car is 10 years young, you know.

Are there any trouble lights on the dash? What happens when you turn your heater/AC, et al, off? Do you still get blowing hot air? If your AC pulley spins up to get the AC going, it can't be a blown belt, or mounting issue. As always, check it out with your local Toy Stealership.

If your heater core went sideways, prepare to empty your wallet.

H&K-Guy

quote:

Originally posted by H&K-Guy:
I'll take a stab at it.

Blowing hot air sometimes means you need to charge up the AC. At least I hope that is the issue. Are there any trouble lights on the dash? What happens when you turn your heater/AC, et al, off? Do you still get blowing hot air?

If your heater core went sideways, prepare to empty your wallet.

H&K-Guy

I'm pretty well sure that the AC is working fine, it's just over powered by something causing the heater to come on HOT, and unable to turn it off or regulate it.

It's not the same as a non-functional air conditioner blowing hot air. This is HOT as in full blast hot out of the heater vents in winter time when the engine is all warmed up.

Thanks

It's most likely your ac/heat, fan speed, etc. selector panel that has gone bad.

Odd. Just odd.

Blowing HOT air when everything is turned off. I just don't know. Hopefully a real Toy mechanic on SigForum has a better answer.

H&K-Guy

I suspect a bad electric air blend door actuator. It regulates the air flow through the heater core and evaporator. Others operate the vents (dash, floor, defrost) and the fresh/recirculated air door. There are on the heater core/evaporator case under the dash, and typically look like this:



The little motors in them can go bad, or one or more of the planetary gears inside can strip. Hopefully it will be accessible without taking the whole dash out.

quote:

The little motors in them can go bad, or one or more of the planetary gears inside can strip. Hopefully it will be accessible without taking the whole dash out.

I wish this for you so much. I had to replace mine in an Explorer heavenly lord I had no reason to ever want to know how to disassemble the entire dash. It was awful.

Sounds more like a control head problem than a blend door motor. OP states he couldnt turn the heat off no matter what he does, if this is the case then a control head seems likely. Even though its the standard 3 knob type its still a circuit board/fly by wire system, in some Toyotas the control head is actually a small computer under the dash/passenger foot rest area. I can look it up tomorrow at the shop if you like.

quote:

Originally posted by Jaywendland1981:
Sounds more like a control head problem than a blend door motor. OP states he couldnt turn the heat off no matter what he does, if this is the case then a control head seems likely. Even though its the standard 3 knob type its still a circuit board/fly by wire system, in some Toyotas the control head is actually a small computer under the dash/passenger foot rest area. I can look it up tomorrow at the shop if you like.

Yes please, I'd appreciate that.

There is about 8 wiring diagrams for the a/c control system for your vehicle, the 2 units i would suspect are called the a/c dash control unit, and the a/c computer, also called the a/c amplifier. I cant tell you which one is the issue without actually testing myself, Looks like the amplifier is about 250$ and the control head is 700$+, thats toyota list prices, might be cheaper aftermarket.

quote:

start the engine, the light that indicates the rear defroster is on is now blinking at a steady rate for maybe 20 seconds

What I found:

quote:

The flashing light is the system testing itself or trying to recalibrate the blend door.
It's called the EBL status indicator. (EBL is Electric back light or something, means the rear window defroster)

Seems you may have a malfunctioning blend door or other climate control problems.

and

quote:

the background....
when starting the jeep it has to go through its own internal air door calibration routines.. which I guess involves running the doors from end to end and taking encoder readings along the way. the encoder is what tells the HVAC control head what position the doors are in. the motors on the doors slowly drive the doors from end to end (stop along the way depending on position called for). the doors control the amount of Heat-mix (temperature knob).. and the air-mode ..(floor, def, etc).. they are electrically driven (not mechanical or vacuum)..

Hope that helps

BTT. Whatever you find, I want to know. I may run into it.

Will do. I took it in to the shop this morning. No news yet.

quote:

Originally posted by egregore:
BTT. Whatever you find, I want to know. I may run into it.

Ok, here's the scoop. To clarify, I was told the dash had to be pulled out to access the Blend Door Actuator, which is where the heater core and AC evaporator assembly is located.

Labor would be 6.5 hours ($650 labor) and the part would be $175-ish.

Once they got the dash pulled out and able to access the area, it turned out that part was not bad, it was another one.

As I understand it, there are 3 Blend Door Actuators. One of them has 2 motors on it, and the other 2 each have 1 motor on them. One is for the defrost level vent outlets, one is the for dash air outlets, one is for the floor level outlets, and the 4th one is for the hot-to-cold control. When you select the dash controls to do what you want, these are the devices that make it happen.

Turns out the defective one was the one with 2 blend door actuators on it, and that sucker cost $340-ish.

The work was done, cost right at $1,000 and now works just fine.

I was informed that there are no after market parts for this, it's all factory, and I think the maker is Denso. I have the old part, and it's really just not much at all to look at, doesn't look like it should cost that much.

This is how I understand it, and there may be some details that are not quite accurate, but I think that's the gist of it.

I had asked if I might have dash squeaks and rattles when the did this, and was told that they'd obviously do their best, but lots of things are plastic, the car is a 2007, so they couldn't guarantee no squeaks or rattles, most of the time there are none, but occasionally some car would have an issue. I'm happy the job was done just fine, everything works properly again, and I have no squeaks or rattles.

Hope this helps you if you run across it in your career.

Thanks. I did one of these actuators on a Lexus RX, but it was accessible without pulling the dash. GM vehicles seem to be particularly bad for these, often accompanied by clicking and snapping as the motor tries to "find" its "home" position.

quote:

Hope this helps you if you run across it in your career.

I have. The new blend door motor for my Grand Marquis cost me $40 and it took a couple of days of tedious work to get to it buried deep within the dash and replace it. There's not that much to them so the part price(s) for yours are puzzling. I can understand the labor costs, though. What a PITA.

Glad you got it fixed.