rear blower sometimes goes to high by itself (1 Viewer)

[Jim_Chow]

The rear blower on my wife's LX sometimes randomly turns to high. This occurs regardless of whether the A/C is on or off. Of course, when the rear air button under the nav up front is "off," it doesn't happen. The dealer has never been able to replicate the issue since it doesn't occur often enough (maybe once every other day). Ever since we wheeled it about 80 mi offroad a couple of months ago, it's been doing it more often (before that, it didn't so it for at least a year). BTW, when the rear blower goes into high by itself, the light on the "high" switch illuminates, as if a ghost had pressed the high button.

Since the rear AC and blower seem to work correctly when you use the rear low-med-high fan speed switches in the ceiling, the only thing I can think of is a faulty rear climate control switch. Opinions?

 

[Copenhagen1]

I cannot answer your question but I can bump it back to the top.

I am still trying to figure out how to control my rear ac/heat in my new to me 2001. I know the "rear" button on my dash under the radio is like a master switch. It seems to control whether or not there is power to the rear controls or not.

When the "rear" button is on, the person in back can control their atmosphere kind of like the front passenger and driver. They can touch the automatic button on the rear control and then set the temp with the sliding temperature switch. It seems like if it is warm outside and the automatic button is on and the slide switch is all the way towards blue, the fan will be on high until it brings the temp down. Then it should automatically bring the fan speed down to medium then low.

The first two hour trip I took to Dallas in this truck, my passenger in the backseat set it up the way I just described. It blew on high the whole two hours there and the whole two hours home. It was about 80*F outside. Seemed to me like it wasnt working properly. I am still figuring it out.

I did find this when I searched but it is way over my head. I'm a decent mechanic but not an electrician. If it is over your head too, it would be a great thing to print and take to your mechanic.
https://forum.ih8mud.com/100-series-cruisers/249889-heater-ventilation-fan-blower-question.html

 

[NMuzj100]

I had a rear seat passenger who's booster was the perfect height to kick the rear controls and was always turning on the heat when I was trying to cool the truck.

the only thing I can think of is a faulty rear climate control switch. Opinions?

Could also be a faulty front switch ?

Does the 03 have controls on the rear of the center console or only on the ceiling?

 

[OregonLC]

If you cycle (turn on/off) the dash-mounted rear switch you will lose your rear settings (at least for model year 2000). I have mine set on overhead vent, medium fan, mid temp, which makes for a happy hound and fog-free windows. Leaving the forward switch on, my settings do not change even after a restart of the vehicle. In 2000 the rear controls are overhead.

 

[ckkone]

If you cycle (turn on/off) the dash-mounted rear switch you will lose your rear settings (at least for model year 2000). I have mine set on overhead vent, medium fan, mid temp, which makes for a happy hound and fog-free windows. Leaving the forward switch on, my settings do not change even after a restart of the vehicle. In 2000 the rear controls are overhead.

It works the same on my 99', will lose the setting if I toggle the switch up front.

 

[mcewan13]

Our rear blower kicks on by itself randomly as well. I'll be driving along wondering if a window's cracked bc I think I hear road noise and then notice the green light below the nav is on again.

 

[OregonLC]

Our rear blower kicks on by itself randomly as well. I'll be driving along wondering if a window's cracked bc I think I hear road noise and then notice the green light below the nav is on again.

Strange. With the rear fan in Auto it will take off on it's own, but I've not seen the rear controls become enabled without the button being pushed. When the front switch is off, it stays off for me.

 

[jatman]

Interesting, this just started happening to me within the last two weeks. I noticed it a few times over a couple of days when I had the rear on. I usually have it on when transporting the kids or taking folks to lunch during work. When it is was doing it, a passenger turned the rear off (on the rear panel) and then set the controls back on to auto (the controls had been set to 75 and auto, since I bought the truck, never really adjusted). I haven't heard it since. Not sure if that did anything or there was some funny business with the combination of weather and sensors (assuming there is a sensor for the rear air auto)...

 

[re_guderian]

Mine's always been like that. I leave it on high (life support...) pretty much year-round...

 

[Liam]

mine does the same thing. It's not on auto, but for some reason it will kick on randomly..

 

[NMuzj100]

This sub contractor no longer makes AC controls for Toyota ...








They now work exclusively on drive-by-wire technology.

 

[rusty_tlc]

Mine never comes on, ever, as in even when I want it to.

Last night I had passengers in the back, the outside temps were in the teens. They were not happy.

i think I should attend to this.

 

[sdnative]

Bringing this thread back up as I didn't see any other relevant ones. Just wondering if anyone has determined the cause or a solution.

My rear AC fan will randomly turn on by itself.

The rear control will be set to auto with the front set to off (which will turn off the indicator lights on the rear controls). Occasionally I will hear a fan noise and look down to find the front control rear AC light on. A few times while driving this has happened and just yesterday while working on the truck with the key in the ON position.

I am not sure if this is normal behavior, but I notice when I turn the control to Auto using the rear controls, the front Rear AC control will light up. I thought the front was the master control and overrides the rear?

Is there a separate climate control ECU? Where is this located? I suppose this is / could have been damaged.