Why Does Toyota Tacoma A/C Only Work On High? (Solved!)

The Toyota Tacoma is Toyota’s headline pickup truck that has been around since 1995.

It comes in three body styles: Access Cab with Long Bed, and Double Cab with either Short Bed or Long Bed.

It’s powered by either a 2.7L or 3.5L inline-4 engine and gets up to 278hp paired with a 6-speed automatic or manual transmission.

This article answers the question “Why Does Toyota Tacoma A/C Only Work On High?”…

Why Does Toyota Tacoma A/C Only Work On High?

The main reason that your Toyota Tacoma A/C is stuck only working on high is most likely because of a failure in your blower resistor. When the resistor fails, the fan will default to the highest speed because there is no longer any limit on the amount of voltage being received.

The resistor is designed to limit voltage according to your current A/C settings, which allows it to run either slow or fast.

Toyota Tacoma Blower Motor Structure

The main components of the Toyota Tacoma A/C blower motor include the motor switch, the motor fuse, the motor relay, the resistor, and the blower motor itself.

The switch completes the circuit, bringing the fuse, relay, and resistor to life as the blower starts to operate.

Below we’ll explore some of these components in more detail.

The resistor’s main job is to regulate the voltage that reaches the blower, which in turn allows the user to adjust the blower strength.

More resistance means less voltage, which makes the fan turn more slowly.

As the user adjusts the strength of the A/C, the resistor yields, and more voltage gets through.

Blower Motor Switch

Issues with the Toyota Tacoma a/c fan blower motor switch are fairly common in the Tacoma, especially in models from 2005 onwards all the way to the present day.

The switch itself is a replacement part with just the lower part costing around $100 from the official Toyota parts center.

If you want to know if your Tacoma blower switch has gone bad, you can check for three main symptoms:

  • The switch is currently only working on certain settings
  • The switch is getting stuck easily
  • The switch knob itself is physically broken

Blower Motor Relay Wear Out

In the Tacoma blower motor, the relay’s job is to supply the power which makes the fan circulate the air. It works quite a lot like an on/off switch.

When in the ‘on’ position, it sends and controls the flow of current between the blower motor and its power source.

When the blower motor relay develops a problem, then the result is poor power distribution and that could risk blowing the fuse and cutting the power to the blower motor completely.

If you detect inconsistencies in the cooling/heating of your Toyota Tacoma, then the main cause for this could be a problem in the relay.

A faulty relay creates uneven power distribution, which in a best-case scenario, creates uneven cooling, but in the worst case will blow the fuse.

If the A/C blower motor doesn’t turn on at all, then this is also likely due to a problem with the relay.

Toyota Tacoma Blower Motor Resistor Not Working

When the Tacoma blower resistor stops working, it means that the regulation of voltage is reaching the blower fan is no longer happening as it should.

The most obvious sign that your resistor is not working properly is that your blower fan is stuck in “high” mode or only seems to blow at the highest setting even when you try to adjust it to a lower, slower-blowing setting.

Another possibility is that the resistor is active but not adjusting. In this case, you’d notice that the blower fan is only able to operate in a lower speed setting.

If the resistor is active, then the voltage will be restricted but if you can’t adjust the resistance then you won’t be able to speed up the fan.

To fix the resistor you will most likely need to replace it, which can be done fairly simply with the right tools.

The resistor is located usually to the left of the motor blower, which itself is under the dash on the passenger side.

The resistor itself unbolts and removes easily, and you can attach a new one with relative simplicity.

Don’t attempt the replacement if you don’t have either the experience or proper tools, though.

How To Test The Blower Motor?

The best way to test your Tacoma blower motor is to use a multimeter set to read on the Ohms scale.

There are only two wires coming from the blower motor, one of which is black (negative), with a positive wire of another color, possibly purple.

These detach from the blower motor via the connector very easily.

Pull out the connector and then you can test each wire in the multimeter.

Once connected, turn the heater to full power and have your multimeter set on DC.

If you get a reading of “no current,” then you know that the blower motor is faulty.

Where Is The Blower Motor Located In The Tacoma?

The blower motor on the Toyota Tacoma is very easy to find.

It is located on the underside of the dashboard on the passenger side.

If you take your smartphone, turn on the flashlight, and take a look under the dash on that side, you’ll see a round-black housing. That’s the blower motor and fan.

To the left of that with four wires emerging from it you will find the all-important resistor.

Blower Motor Control Module

The blower motor control module in the Tacoma is responsible for helping to control the air supply to the passenger cabin via the A/C system.

It is there in particular to control the production of cool air in the A/C system and that once produced it is circulated through the passenger compartment.

If you notice that your A/C cooling fans are running for a very long time, much longer than before, then it’s a sign that your blower motor control module might need replacing.

The same goes for when the cooling fans are not running at all or when there is any weakening in the airflow.

The control module is meant to keep everything running smoothly.

If you notice any erratic delivery of air or overactive components within the Tacoma A/C system, then the control module fault is likely to blame.

How Much Does A Blower Motor Cost For A Tacoma?

It’s not a cheap component to replace.

The Toyota Tacoma blower motor can cost up to $200 to replace when you factor in the labor cost, which is likely to reach between $35 and $45.

The parts are the most expensive element at roughly $160 for a new blower motor.

It should be noted that this cost could vary depending on your geographical location and the additional application of taxes and other fees.

How Long Should My Blower Motor Last?

A well-designed and maintained A/C blower motor in your Toyota Tacoma should last you as long as the vehicle itself.

This doesn’t mean that it won’t run into any issues or not be in need of repair.

The point is that you shouldn’t have to fully replace the blower motor unless something major happens like a collision or some extreme climatic conditions render it damaged beyond repair.

Dirty Blower Motor

Over its regular lifetime, a Toyota Tacoma blower motor will naturally accumulate dust and dirt.

Its location under the dashboard on the passenger side means that it is exposed to the dirt brought in on passengers’ feet, as well as the general accumulation of dust that will build up as long as the car doors are opened and the air is allowed to enter the cabin.

When the blower motor gets dirty, it can negatively impact its operation.

Dirt accumulation on the blower motor is as much of a problem for it as electrical or mechanical failure, so regular cleaning of the blower motor is a good idea to remove dust and other contaminants.

How Often Should I Clean The Blower Motor?

Cleaning the component itself is best done by a professional since it may need to be removed and safely and properly cleaned.

What you can do first as a Tacoma owner however is clean the inside of your Tacoma weekly to reduce dust and dirt accumulation in the cabin.

This will reduce the amount of dust and other contaminants that the blower motor is exposed to.

As for the blower motor component itself, an annual cleaning is a good idea to ensure that the blower motor can always operate at optimum performance.

Blower Motor Relation With The Compressor

Your Tacoma blower motor and the A/C compressor are two components within the same overall system.

They are connected via an intricate climate control wiring harness fuse and relay, but they perform somewhat different functions.

The blower motor moves air with just a moderate increase of pressure whereas the A/C compressor packs air into a much smaller space, making it denser.

The compressor’s role is more in the cooling process of the air rather than the actual blowing of it into the cabin.

Other A/C Problems

Besides issues with the blower motor and air being stuck on a high setting only, there are other common problems with the Toyota Tacoma A/C system.

These include, but are not limited to:

  • Weak airflow caused by weakened fans, seals, or hoses
  • Mold buildup causing airflow problems and bad-smelling A/C (especially in the 2016 model)
  • Malfunctioning compressor clutch
  • Refrigerant leak
  • Blown fuses