Alternator not maintaing voltage

[tirod]

We see this in the US a lot.

Exactly - the reference voltage that feeds the voltage "load" to the regulator was routed back to +. That means it had nothing to turn it on and make it work. It can't sense what the electrical draw is on the wiring at the main load connection. That's usually at the first + connection where all those wires get bolted to one stud. There, the voltage drops due to load, and it's the best place to reference when to turn on the alternator.

"One wire" alternators references it's own output voltage. Most won't even start charging until they spin above a set rpm, 1700 to 2500. Idle around in normal driving all day and it drains the battery.

They were invented for farm tractors, not cars. Some people just carried the concept over for hot rods because they didn't want to mess up their work of art with actual wiring. What makes it worse is to add a underdrive pulley, then they don't spin up at all, and adding a gel cell high cap battery then disguises it's inability to charge up. Basically they cruise around on the battery, then put it back on a float charger until next weekend.

It's actually quite common now, all the "best" hot rod parts, and they don't work as a system well, if at all. And - if someone repeatedly has their battery warrantied out, most parts houses and vendors will finally just refund their money, to get out from under the bleeding costs. That leaves the owner going from store to store until they finally take off the wrong parts in disgust and install the proper alternator wired back to sense the load.

Just say no to one wire alternators - unless it's for your tractor.