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Toyota Tacoma No Heat: Common Causes and How to Fix

Toyota Tacoma No Heat: Common Causes and How to Fix

It can be frightening when you crank the heater to max defrost, and it only blows cold air.  Unfortunately, this happens not only to the Toyota Tacoma but many vehicles can have no heat issues. The issues are caused by common occurrences and are easy to fix.

The most common reason a Toyota Tacoma has no heat is because the heater core is bad or it has a blown fuse. Other reasons include a bad blower motor, the coolant level is low, or the water pump is faulty.

The fixes only sound complicated; in reality, most of these parts are plug-and-play parts. The hardest part is identifying exactly which one of them is the culprit behind the loss of hot air inside the cabin of Tacoma.

Why is my Tacoma blowing cold air and not heat?

These occurrences are common causes in most vehicles, not only Tacoma’s. Yet, most of the time, the solution is an easy trip to the auto parts store or your local big-box retailer that carries the parts needed.

  • The Coolant Level is Too Low
  • The Water Pump Is Bad
  • The Heater Core is Bad
  • One of the Fuses or Relays is Blown
  • The Blower Motor System

Here’s a video with a basic walk-through with more info and common causes below:

Check out the most popular Tacoma Accessories Here from Amazon

The Coolant Level is Too Low

Like most fuel-powered vehicles, the Toyota Tacoma uses the heat from the antifreeze mixture and passes it through a heater core to produce the hot air that comes out of the ventilation system.

The Heater core is usually located between the firewall and the inside of the vehicle behind the dashboard in the lower center portion of the cabin. As the coolant is pushed into the heater core from the water pump, the heater core acts as a cooling system for the coolant.

The cycle is continuous, and there needs to be enough coolant inside the vehicle to efficiently produce enough heat for the inside of the truck.  The air is taken from the heater core and pushed through the ventilation system to warm the cabin.

When there is not enough coolant to push through the entire system ( radiator, engine block, heater core, etc.,.), the coolant does not stay in the heater core long enough to produce heat.

The coolant does not stop inside the heater core; the fluid is moving continuously, so the less coolant inside the reservoir (below the low coolant line), the higher the chance that it will not be enough hot liquid to produce the hot air needed. Therefore, check the coolant levels in the vehicle and add coolant as necessary.

The Water Pump Has Gone Out

The water pump going out is less standard than the other issues in this list. However, there will be definite signs of the vehicle overheating regularly, which could cause irreparable damage to the engine block.

The heater going out on the Toyota Tacoma could be working irregularly if the water pump is starting to show signs of failing.

These Telltale signs include:

  • The heater blowing semi-cold air after the Tacoma is fully heated ( about 180-220 degrees)
  • The heater blowing irregular temperature air (cold, then hot, then out)
  • The Tacoma overheating
  • The water pump makes whining noises
  • There is coolant leaking from the water pump
  • Steam is coming off of the radiator when it is not supposed to be ( like in the summertime)

The water pump is the least likely culprit of the heater not working correctly. However, it should be addressed. Instead, replace the water pump when needed (have a mechanic do this; you can mess up the timing on the engine if you do it wrong).

The Heater Core is Bad

The heater core (discussed above) could be going out also. The most common sign that the heater core is going bad is the sweet smell of antifreeze ( yes, it smells sweet).

Some other telltale signs include coolant loss and foggy windows when they should be defrosting. Replace the heater core with a new one (remember to drain the coolant from the radiator and reservoir first. Otherwise, you will have a giant mess inside the cabin)

Will a blown fuse cause my heater not to work?

A blown fuse could cause the heater not to work for various reasons. However, a fuse is often easily identified and replaced for only a few dollars.

The most common fuses that could cause this issue are:

  • Dashboard control fuse
  • Interior blower motor Fuse ( located inside the cabin fuse box)
  • Exterior blower motor fuse (located underneath the hood fuse box)
  • A/C system fuses

A Bad Relay Switch Could be the Culprit

If you have checked the fuse box and all of the fuses seem in good condition, the next culprit could be a relay.

The relay works almost like a switch with a fuse inside. The relay acts like a fuse but is a controllable component that resets every time you turn the switch on or off.

In Tacoma ( and most vehicles), the blower motor relay is the culprit. The blower motor is a fan that blows the hot air radiating off of the heater core through the ventilation system. It is a plastic wheel attached to a motor controlled by the user input on the dashboard.

When you select heat or cool air and the fan speed, electricity rushes through the relay and allows the fan to spin at the rate needed to produce the desired temperature inside the cabin.

The Blower Motor Itself Could Also be Faulty

If the relay is not the culprit, it might be time to look into the blower motor itself. This part sometimes goes out and has similar symptoms to the fuse and relays going out ( the motor doesn’t blow any air at all).

The Blower Motor Resistor (lower and Upper)

Typically if the Tacoma is blowing air ( hot or cold) at only one speed, the blower motor resistor could be the problem. To make the blower motor spin at the correct speed, the resistor provides the calculated resistance from the electricity flow coming out of the relay.

When the resistor goes bad (upper or lower), the fan is either spinning too fast or too slow to regulate the temperature.  

Replace any of the parts mentioned above, the fuses, relays, or motors are all easily accessible and for a low cost.

Check out the most popular Tacoma Accessories Here from Amazon

These are the Most Common Causes; There are Others

There are other causes of the heater not blowing warm air, but the ones in this article are the most common causes and fixes for the Toyota Tacoma. Most of the parts are easy to obtain and are commonly out at most auto parts stores.

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