What’s the TREC Fuse? (Explained)

Understanding which fuse does what in your car helps you identify and get over most electrical issues in no time. This way, you can easily pull out a blown fuse and replace it as soon as possible. The TREC fuse, like other fuses, is one of the most critical components of your car. Once you can locate it and what functions it performs, you won’t have an issue carrying a DIY repair on your car. 

If you’ve been trying to learn more about the TREC fuse, here’s an opportunity. Let me walk you through the specifics of this vital part of your safety. 

What does TREC Fuse mean?

The TREC fuse, or 4WD fuse, is the fuse that provides power to the transfer case control module (TCCM) of your car. Apart from the TCCM, the TREC fuse also powers the Transfer Case Encoder Motor (TCEM) and Shift Control Module (SCM). Besides, the fuse protects the TCCM from overcurrent and electrical surge that often threatens many fuses in the fuse box. Regardless of the vehicle make or model, the TREC is a 30 AMP fuse that 

While the function of the TREC fuse remains the same in all cars, its position differs. Depending on the type of car your drive, the TREC’s location varies by vehicle, and I’ll tell you this shortly. But suffice it to say that the TREC fuse is critical to the proper functioning of the TCCM. After all, the TCCM is the brain behind the 4WD systems, especially the electronically shifted systems.  

Where is the TREC Fuse Located in Chevy Silverado?

The TREC fuse in your Chevy Silverado is located under the hood of your fuse box. You can find the underhood fuse block on the driver’s side in the engine compartment. It is near your car battery. If you need to diagnose any issue say a blown fuse, open the fuse box. Simply press the fuse box clips and tap the box open. 

Where is the TREC Fuse Located in the 2003 Tahoe 5.3L?

If you own a 2003 5.3L Tahoe, the 30amp TREC fuse is located in the underhood fuse block. To uncover the fuse, simply remove the lip and lean over the fender. Take a look at the first row of the fuses lined up and closest to the fender. Check from the right rear side for the second fuse. That is the TREC fuse. It performs a similar function as in other vehicles. 

Where is the TREC fuse located in Ford Expedition (2009-2014)?

You’ll locate the 4WD fuse (as the TREC fuse is often named in 4×4 vehicles) in the Ford Expedition (2009-2014) under the front hood in the main fuse box. Simply tap the right and left tabs to open the fuse box. Check the backside of the fuse box cover. It’s a 20amp fuse.

Why Does the TREC Fuse Keep Blowing?

This is a frustrating concern for most 4WD owners. Each time you want to engage the four-wheel drive, the TREC fuse keeps blowing, right? Here are things I have found to be potential culprits. You’d do well to check them.

Broken Vacuum lines

A broken vacuum line can cause the TREC fuse to blow each time you try to use the four-wheel drive. What is a vacuum line? The vacuum lines run from the center of the firewall to the solenoid. It’s located beneath your car’s battery shelf. If any of the lines get broken, they can affect the fuse and cause it to melt and blow. The lines break due to contamination with acid that leaks from the battery. The acid finds its way under the battery shelf and mixes with the vacuum lines. The thing to do to remedy the situation is to replace the vacuum hose and you’re good to go. 

Faulty Diaphragm

You can also attribute a blown fuse to a faultydiaphragm valve. The diaphragm actuator is also located underneath the battery shelf. Once it goes bad, the TREC fuse may blow. The diaphragm or solenoid valve connects via a vacuum hose to the TREC fuse. It works with the actuator cable that runs to the transfer case control module. You can replace the diaphragm once you suspect it’s gone bad. It’s that simple. 

Overcurrent on the shift control motor

There is a chance that the TREC fuse will blow when the shift control motor draws excessive current. So, you should ensure that the shift sensor is in good condition to monitor how much current gets to the transmission. If the transfer case gets jammed up, it could also blow the fuse. To diagnose and fix this, first, disconnect the connector of the shift control motor to check if the fuse has blown. If the fuse is still active, take off the shift control motor from the transfer case. Reconnect it back to the harness. See if the fuse will blow. If it doesn’t, then your car’s transfer case is having issues. If the fuse blows, then the shift control motor is faulty. Replace the transfer case or shift control motor, as the case may be.


Is the TREC fuse the same as the 4WD fuse?

I’ve received loads of questions as to whether the TREC fuse is the same or performs a similar function as the 4WD fuse. Car owners and some mechanics often use the two fuses interchangeably. My answer remains the same: there’s a slight difference between a TREC fuse and a 4WD fuse. Meanwhile, the functions of these fuses overlap in most cases. In most cars, the 4WD is a 15amp or 20amp fuse while the TREC fuse mostly consists of 30 amps. If you drive a 4×4 vehicle, like the Ford Expedition, the TREC fuse is tagged the 4WD fuse. The function is the same. 

Final Thoughts 

So far, I’ve explained what the TREC fuse is, its location, and its functions. The next time someone asks you, ‘what is the TREC fuse?’ I am sure you can explain. You won’t take it to mean the Texas Real Estate Commission. Lol! You should try to prevent the fuse from blowing, and when it’s blown, try to remove and replace it. I hope this helps. Have a safe trip.