Vent blowing warm air?

Hi All.

It's been awhile since I've posted here.

My 2013 Double cab SR5 Prerunner (110k miles) has recently begun blowing warm air through the cabin vents with the temp control set as far CCW (coolest) is possible without activating the A/C compressor...(which I find to be an annoying "feature"). That setting USED to bring in air at the ambient external temperature, but now it seems as if the control was set to about the "9 0'clock" position, or thereabouts (low heat setting). I can overcome the problem by turning on the A/C, which then blows cold air into the cab, but that's not a very good solution... and the warm air will diminish the efficiency of the air conditioning.

Has anyone else experienced this? Would the problem be in the control itself, or the valve that regulates how much hot coolant gets routed into the system?

It's going to start getting warm here in Florida, so I thought I'd see what I could do before then.

Thanks in advance.

Tony

 

You're overthinking it man. The air is coming out warm because is goes through a warm area on it's way out the dash. Just use the a/c

If the dash vents are set windshield defrost then it's running the a/c anyway

 

I feel like this is normal operation for all the vehicles I've ever own.

More than likely you're just noticing it now and it isn't actually a change in condition....that's my thoughts at least.

 

The a/c is more than capable of turning that warm air into cold air. The modern a/c systems are way more efficient than they used to be, they don't kill your gas mileage anymore

 

There is no longer a hot water valve that controls the water flow through the heater core. These days the hot water flows through the heater core all the time and there is a blend door that regulates how much hot air mixes with the ambient or cold air that is regulated by a servo motor.

 

Thanks for the replies. I'm reasonably sure this is not something that has been going on a ling while - I've put all of the 110k miles on the truck myself, and I'm pretty well tuned into what's "normal". The warm air is noticeable even when it's cool out, and the "recirculate" setting is off. 72° outside air should not feel significantly warmer than air coming in through the windows at low speed.

Jimmy's comment has me wondering if the "blend door" might be jammed in some way, allowing warm air to flow into the system... is it in the cabin under the passenger side of the dash?

What would be the best way of checking it?

Thanks again.

 

Here is where it is.The Blend between hot and cold is controlled by the "Air Mix Control Servomotor" in the drawing below.

I suppose you could remove the servomotor and manually move the blend door by hand to ensure that it isn't binding. There are only three bolts and an electrical connector.

 

Thanks Jimmy! That is EXACTLY what I had in mind, and EXACTLY the drawing I needed! You ROCK!

I was also considering activating the servomotor while observing its motion (or lack thereof), and (if needed) measuring the voltage/signal to it (with a DVM or O-Scope).

Looks like it's easily accessible from under the passenger-side dash.

Tony

 

Jimmy -

Thanks so much again, for the drawing - everything was just as illustrated, but a real B*TCH to get to without dropping the center console. I didn't - just the glove box (which is why it was such a contortionist act to get to).

I found that the actuator was working as it should, but the actual vane that it moves (which "mixes" the hot & cool air) was being partially blocked at the "almost closed" position, by some errant foam weatherstripping, which probably was part of the seal. I exercised the vane manually, in a rapid and aggressive fashion, and the blockage cleared. Problem solved. 45 minutes of cussing to get it all reinstalled "blind", and problem fixed.

Once again, TW members come through! This probably would have cost me hundreds at a dealership, requiring replacement of the airbox, actuator, and who knows what else. And they probably would have bolluxed up my stereo wiring in the process...

 

Glad you got it sorted out!

 

Glad you posted and found a solution. I'm experiencing the same problem. I remember the vent being cooler and kept second guessing myself that maybe it was me. The kicker for me was I had the center console out last weekend for something else and forgot to check the vent.