Throwback Thursday: To Use A One-Wire Or Three-Wire Alternator – Chevy Hardcore

For the last several years, there has been a debate raging about alternators. One side feels the traditional set up is best, while the other screams the virtues of one-wire units. For that reason, I thought we would focus this weeks Throwback Thursday on One-Wire Or Three-Wire Alternator: Theres No Wrong Choice.

During the 60s and 70s, the output of the alternator was simply used to sustain the power needed to run the engine with the headlights on. The only electrical accessory was an AM radio. There wasnt a need for high-amp alternators. The addition of fog lights, driving lights, amplifiers, and other high-powered accessories had not really hit the market very heavily until the 1980s.

Tuff Stuff alternators are usable in both one- and three-wire installations. With a one-wire install, simply connect the charge wire from the alternator battery post (left) to the battery. Tuff Stuff does recommend upgrading the charge wire to a larger gauge (smaller number), as the factory wiring might not be capable of carrying the extra amperes without melting. If you plan to use the factory three-wire installation, install the charge wire to the post, then remove the black plug (right) and connect your factory two-wire connector.

In the original article, we talked with the professionals at Tuff Stuff Performance to find out if there is a benefit to one or the other. Whether using a one-or three-wire alternator, its function is to recharge the battery. As lights and other accessories draw current from the battery, energy is replenished by the alternator.

To keep the battery fully charged, the alternator must provide more amperes than the accessory load on the battery. A common myth is that a higher amperes-output alternator can hurt the battery. That is not true. If the voltage regulator is properly functioning, it will safely keep the battery fully charged and ready for use.

If you are starting a project from scratch or you want to minimize the number of wires in your engine bay, a one-wire alternator will simplify the installation. The only drawback to using a one-wire alternator in GM vehicles has to do with the ALT warning lamp (idiot light) on the dash. A one-wire alternator doesnt use the two-wire connector which supplies electrical current to facilitate use of the idiot light. The two-wire connector houses the exciter wire, which is responsible for turning off the in-dash light.

Tuff Stuff alternators like the7127,7139, and7140series can be wired to turn off a warning light. To wire a warning light using one of these battery chargers, simply remove the black terminal plug on the housing and connect the R terminal to the warning-light wire.

A major benefit to using a Tuff Stuff alternator is the fact it can be used as a one- or a factory-designed three-wire system. Using the alternator in either instance requires no extra effort on the part of the end-user. If you want to use it as a one wire, connect the charge wire to the battery and alternator, and youre done. If you wish to use the three-wire system, connect the charge wire, remove the black plug at the two-wire terminal location and plug in your wiring. Its that simple.

Theres a lot more in-depth information in the original article, and for that reason, I selected, One-Wire Or Three-Wire Alternator: Theres No Wrong Choice as this weeks Throwback Thursday showcase article.

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Throwback Thursday: To Use A One-Wire Or Three-Wire Alternator - Chevy Hardcore