One of the biggest challenges with owning a classic truck is that the old electrical systems can’t keep up with modern upgrades. If you want to add things like air conditioning, a good stereo, or bright off-road lights, the stock 75-amp alternator just isn’t going to cut it. Jacob from Jacob’s Upgrades recently tackled this exact problem on his 1979 Ford Bronco, documenting the process of swapping in a new Bronco one-wire alternator from Tuff Stuff.

Out with the Old, In with the New

The project involved converting from the factory’s three-wire, externally regulated system to a modern, internally regulated 140-amp Tuff Stuff one-wire unit. After removing the fan and shroud for better access, Jacob highlighted a key benefit of modern technology. “You can see a huge jump in technology has allowed alternators to reduce in size yet increase in capacity while also including internal voltage regulators,” he noted, showing how the new, smaller unit packed a much bigger punch than the bulky original.

Wiring the New Bronco One-Wire Alternator

The wiring conversion is the most important part of the swap. Jacob showed the three important steps to get it right. First, he ran a new, thicker charge wire from the alternator to the starter solenoid, making sure to install a 150-amp in-line fuse for safety. Second, he added a dedicated ground wire from the alternator casing directly to the engine block. Lastly, he addressed the old factory wiring by taping off the two unused wires and, most importantly, unplugging the old external voltage regulator. 

The Payoff: Powering Modern Accessories

After running the new setup for over a month, Jacob’s verdict was clear. “I’ve been running this for a little over a month now, and it’s been a huge upgrade over the stock alternator,” he reported. The real benefit wasn’t just a more reliable charging system; it was the ability to finally run the modern accessories he wanted. The new, higher-amperage Bronco one-wire alternator could now easily power his Vintage Air A/C system, a modern stereo, and a full set of off-road lights without the voltage dropping.

Was the Upgrade Worth It?

In the end, Jacob’s project answers the question in the video’s title. The move to a high-output one-wire system was more than just an electrical job; it was an enabling upgrade. It allows a classic truck to reliably run the modern features that make it safer and more enjoyable to drive every day. For his ’79 Bronco, the one-wire alternator was the key to bridging the gap between classic style and modern convenience, proving the upgrade was absolutely worth it.