A/C Fan does not work and then it does

On my 2015 Tundra 1794 - I need some help guys, my a/c fan inside, is acting up. Sometimes it works fine, but lately it doesn’t blow. It sounds like it is working on low, but when I press the auto button it stops. So is there a way to tell if it is the resistor or the fan motor. Then the next day it will work fine after I turn it off. Then it starts acting up again.

 

Is the a/c fan different than the heater fan? Does the heater work?

 

The heater works (I said a/c but I met both) when the fan is only working a little bit, and next it works great and then the fan is back to really slow again.

 

Can you increase the blower speed manually and without using the auto? Does the fan work on the highest manual setting? Sound like the answer is no so it could be the blower motor or also check the relays.

I am not familiar with design of Tundra but with older cars typically if the blower works only on high, the resistor is most likely bad. The new cars may have a fancier design. I'm not sure. I've had only one blower motor failure in a very old car.

you need the wiring diagram. Maybe someone can post it.

 

Haven’t had a tundra one fail at work yet, but most of the newer Toyota’s have the resistor built into the blower. Chances are you just need a new blower.

 

So you have auto climate control? If so it will control the fan speed based on what temp setting you have it set to. Maybe that's the issue? Can you manually increase the fan speed?

 

As I recall, blower motor speed on a 2015 is not set by a discrete resistance like older models. I believe the blower motor speed, and virtually everything else in the AC system is controlled by a black box called the "Air Conditioning Amplifier". There are also many other inputs to the AC amplifier that affect the blower speed, and any one of those inputs could be from faulty sensors.

Given the labor involved and the expense of the parts, this will not be a repair where "throwing parts until fixed" is a good plan. Access to Techstream and the 2015 Repair Manual will be essential to systematically diagnose this problem imo.

 

When in AUTO MODE the fan will change speed as cabin temperature changes in a effort to maintain what is set in the display. As the cabin temperature cools (A/C) the fan will slow, when you roll down your window to give a thumbs up to a fellow Tundra owner and let out the comfortable cool air, the fan will ramp up. The same applies to heat. If you adjust the fan speed manually, it will automatically cancel AUTO MODE. If you adjust the temperature setting, AUTO MODE remains. Also of note: On a cold start in AUTO MODE and heat is requested, the fan DOES NOT begin to blow at a high rate until the engine temperature begins to rise (unless DEFROST is selected manually or preset at last vehicle shutdown). In MANUAL MODE there are a fixed number of fan speeds, in AUTO MODE they are "infinite" (it's a smoother ramping up).

 

good to know on this thank you!! Same issue as the OP, and found multiple YouTube vids, but one dude from A1 auto says the resistor is built in on the 2014-2019, but there’s another vid with no year listed that says the resistor is separate. Sounds like I’m in the same boat needing a new blower motor, and it looks like a fairly easy swap. Thanks!!

 

https://www.tundras.com/threads/blower-motor-failing.98394/

 

I had the resistor failure on a taco, well kinda. Passengers screwed up the connections with they big ass feet
From what I understand I was not the only guy with that issue and they started using "built in" resistors to get around that monkey crap

 

I have a 2019 and had to replace the blower motor under the glove box at 30k

 

Just replaced the resistor in my sons ‘12 Tacoma and now all settings of the blower working again… Good Luck!!

 

Hi Bill, mine is 2019 also with 18K (not a far drive to work fortunately) did the blower motor fix your issue? Thanks!

 

It sure did... got it from McGeorge Toyota they had the best price. It's a 15 minute job

 

ordered one from Olathe Toyota. Hopefully it gets her soon. I saw how easy the swap was. Weird as yesterday the air worked great. Day before it had a quarter of the airflow. Always cold though. Hope this solves it. Thanks!

 

Smack the $#it out of the area underneath the glovebox. Works every time for me... Until it doesn't