Why Upgrade to the Derale 16720 Electric Fan Kit on Your Tacoma?

The Toyota Tacoma is a dependable mid‑size truck, but its factory engine‑driven fan can struggle to maintain optimal coolant temperatures during heavy towing, off‑roading, or in stop‑and‑go traffic. The Derale 16720 Electric Fan Kit offers a direct‑fit solution that replaces the mechanical fan with a high‑flow electric unit. This upgrade reduces parasitic drag on the engine, improves throttle response, and delivers consistent cooling performance. By following this detailed installation guide, you’ll gain better temperature control and extend the life of your Tacoma’s cooling system.

Tools and Materials Needed

Gather the following items before you begin. Many are standard automotive tools; the Derale kit supplies most hardware, but having extras on hand can simplify the process.

  • Derale 16720 Electric Fan Kit (includes fan, shroud, brackets, relay, thermostat, and wiring)
  • Socket set (metric and SAE, 8‑19 mm)
  • Wrench set (combination or ratcheting)
  • Screwdriver set (flathead and Phillips)
  • Wire strippers / crimpers
  • Electrical tape and heat shrink tubing
  • Zip ties (assorted sizes)
  • Drill with metal drill bits (for optional mounting holes)
  • Safety glasses and mechanic’s gloves
  • Multimeter (for testing circuits)
  • Flat pry bar or fan clutch tool (if fan clutch is seized)
  • Drain pan and coolant (if you need to remove the radiator for clearance)

Preparation and Safety Steps

Park and Cool the Engine

Park your Tacoma on a level surface and allow the engine to cool completely. Working on a hot engine risks burns from coolant, belts, or exhaust components. Engage the parking brake and chock the wheels for extra safety.

Disconnect the Battery

Always disconnect the negative battery terminal before working on any electrical system. This prevents short circuits and accidental activation of the fan while you’re connecting wires.

Remove the Factory Fan and Shroud

The Derale kit requires removal of the stock mechanical fan, fan clutch, and often the factory shroud. On most Tacoma generations (1995‑2004 and 2005‑2015, as well as 2016+ with the 3.5L V6), the process is similar:

  1. Remove the radiator shroud – usually held by a few bolts or clips.
  2. Use a wrench or fan clutch tool to loosen the large nut securing the fan clutch to the water pump pulley (turn clockwise on most Toyota engines).
  3. Slide the fan and clutch assembly off the water pump shaft. You may need to tilt the shroud to remove the fan.
  4. Set aside all hardware. The Derale kit supplies new brackets and bolts, so the stock hardware is not reused.

If you’re working on a Tacoma with limited clearance, removing the upper radiator hose or skid plate can provide extra room. Always cap the radiator opening to keep debris out.

Installing the Derale 16720 Electric Fan

Mounting the Fan and Shroud

The Derale fan is designed to mount directly behind the radiator (puller configuration) using the provided brackets. Follow these steps:

  1. Position the fan assembly against the radiator support frame. The shroud should align with the radiator core. In most Tacomas, the stock fan mounting points can be reused with the included brackets.
  2. Hold the brackets in place and mark the bolt holes. If the holes don’t line up, use a drill to create pilot holes. For a clean installation, use the self‑tapping screws supplied with the kit.
  3. Secure the fan using the supplied nuts and bolts. Tighten evenly to avoid warping the shroud. Ensure the fan blade spins freely and does not contact the radiator fins or hoses.
  4. If your Tacoma has an automatic transmission cooler or A/C condenser, verify that the fan’s airflow path is unobstructed.

Wiring the Fan and Relay

The Derale kit includes a wiring harness with a relay, fuse holder, and connectors. Proper wiring ensures reliable operation and protects your truck’s electrical system.

  1. Mount the relay near the battery or fuse box in a dry location. Use a zip tie or screw to secure it.
  2. Connect the relay’s power wire (usually red) to a 12V battery positive terminal using the included fuse holder. Install a 30‑amp fuse (or as specified in the manual).
  3. Connect the relay’s ground wire (black) to a clean, unpainted chassis ground. Scrape paint if necessary for a solid connection.
  4. Route the fan power wires from the relay to the fan motor. Use the supplied connectors and heat shrink. The fan’s red wire is positive, black is negative.
  5. Connect the thermostat/switch wire (typically blue or white) from the relay to the thermostat probe. This wire will trigger the relay when the engine reaches target temperature.

Choosing the Power Source

If you want the fan to run only when the ignition is on, tap into an ignition‑switched fuse in the under‑hood fuse box. Many Tacoma owners use the “ECU” or “IGN” fuse slot with an add‑a‑circuit adapter. This prevents the fan from draining the battery when the engine is off.

Installing the Adjustable Thermostat

The Derale 16720 comes with a 180°F‑to‑240°F adjustable thermostat probe that mounts into the radiator fins. Correct installation ensures the fan kicks on at the right temperature.

Probe Placement

Insert the probe between the radiator fins at the upper or middle section, away from any hoses or metal lines. Push it securely so it makes direct contact with the core. Zip‑tie the wire to the fan shroud to prevent movement.

Setting the Thermostat

Rotate the adjustment dial to your desired on‑temperature. For most Tacoma applications, a setting of 190°F is ideal. The fan will activate at that temperature and turn off around 180°F (factory fan clutch engages around 200°F). You can fine‑tune after testing.

Optional: Manual Override Switch

Many owners add a dash‑mounted switch to manually control the fan for extra cooling during low‑speed off‑roading or towing. Wire the switch between the thermostat wire and ground (or use a three‑way toggle to allow auto/manual/off). Consult the kit’s instructions for acceptable switch ratings.

Testing the Installation

  1. Reconnect the battery and double‑check all wiring. Ensure no bare wires touch metal.
  2. Start the engine and let it idle. Monitor the temperature gauge. The fan should remain off while the engine is cold.
  3. Allow the engine to reach operating temperature (195–210°F on the gauge). At the thermostat’s set point, the relay should click and the fan should spin. Airflow should be from front to back (puller).
  4. If the fan does not activate, check the fuse, relay connections, and thermostat adjustment. Use a multimeter to verify voltage at the fan motor when the engine is hot. If the thermostat is not making contact with the radiator core, it may read a lower temperature.
  5. Listen for unusual sounds. A rubbing blade or loose mounting can cause vibration. Tighten brackets as needed.

Common Troubleshooting Issues

  • Fan runs continuously: Thermostat probe is not seated properly or is set too low. Check for a short to ground in the trigger wire.
  • Fan doesn’t turn on: Verify battery positive connection, relay operation, and ground. The thermostat may need to be turned to a higher temperature.
  • Engine overheats with fan running: Ensure the fan direction is correct (puller). Also verify you have proper coolant level and no air pockets.

Maintenance and Longevity Tips

Regularly inspect the fan blade for debris, the wiring for chafing, and the thermostat probe for secure contact. Clean the radiator fins with compressed air annually to maintain max heat transfer. The Derale fan motor is sealed and brushless? – it requires no periodic lubrication. However, if you drive in dusty or muddy conditions, consider using a secondary inline fuse (30A) to protect the wiring.

For owners who frequently tow heavy loads, installing a second Derale fan as a pusher (in front of the radiator) can further increase cooling capacity. The kit’s thermostat can be set to trigger a relay for both fans simultaneously.

Conclusion

Installing the Derale 16720 Electric Fan Kit on your Toyota Tacoma is a practical upgrade that reduces engine load, improves fuel economy slightly, and provides reliable cooling in demanding conditions. By carefully following the mounting, wiring, and thermostat procedures outlined here, you’ll enjoy consistent engine temperatures whether you’re commuting, exploring trails, or hauling a trailer. This project is well within the reach of a confident DIYer and typically takes four to six hours to complete.

For additional guidance, consult the Tacoma owner’s forum at Tacoma World for model‑specific tips, and refer to Derale’s official product page for the latest installation supplement. For a deeper dive into cooling system theory, read this cooling system basics guide.