Re: One wire alternator question
This is so far the best RECENT posting I've found on one versus 3-wire alternators, so I'm going to post my plea for help with MY 1-wire alternator problems here. I've read a bunch of postings! I've also read the MAD Electrical articles on 1-wire versus 3-wire charging systems. They favor 3-wire, for sure. But I have yet to find a significant majority of opinions that favor the 3-wire if stock alternator dash (idiot) lights and wiring harnesses are NOT desired. On my '67 with a 350 engine, which I originally equipped with a 3-wire internally regulated unit, I tried the add-a-diode route as directed by some posts because I had the problem with the engine not turning off with the ignition switch. With the diode in-line, the engine would shut off alright, but the diode got so hot it melted the heat shrink I had over it and I was afraid I was going start a fire. Using after-market gauges and having no desire whatsoever to use the stock in-dash alternator light, I decided, as have a lot of owners, that a 1-wire was the way to go. So, I installed a 1-wire alternator, made sure I had good grounding connections between the battery and frame, firewall and engine. The voltmeter immediately registerd 14+ volts on the voltmeter after the engine started, but this reading lasted only 10 - 15 minutes into my drive, which was a combination of city & highway speeds. Then the voltmeter dropped down to just barely below 12 volts and there it sat while driving for the next 15 minutes. Then, the voltmeter shot back up to 14+ for around 5 minutes then it dropped back to barely touching the 12 volt mark on the voltmeter. I drove for another 20 - 30 minutes and the voltmeter never went back above 12. I got home and parked the car and shut her off. The engine would barely turn over when I tried to re-start. Suspecting that the battery was the reason I was not getting 14+ charging volts, although it was an Optima red-top battery that was only 7 months old. I pulled the battery and put it on an electronic charger and the initial reading was 11 point something volts and the "Per Cent Charge" digital readout was in the teens. On the charging mode, it eventually came up to a "100%" charge on the digital readout and I think the voltage readout was 14 point something. Could that have been right? I unhooked the charger, left the battery stand for 24 hours and then checked the voltage and it showed 12.6 - 12.7 and the "Per Cent Charge" readout was 95%. I don't know if this is normal, but at this point I do not suspect the battery to be bad. So, is my brand new 1-wire alternator now the culprit? I don't know what to try next, because I don't want to go back to a 3-wire because I do not trust the add-a-diode option and I do not really want to track down the dash light wire or go to an externally regulated alternator system, although I have read about an electronic external regulator from Auto Zone that works pretty good---so maybe that's what I'll be forced to do:waste the new 1-wire internally regulated alternator and hook up & re-wire for an external regulator.
Sorry for such a long posting, and if I sound frustrated and defeated, you're exactly right. As I stated earlier, I have scoured previous postings and have not found a complete answer to those who prefer a non-stock wiring and after market gauge (1-wire alternator) system over a 3-wire alternator (internally or externally regulated) dash-light system. And the MAD articles, prejudiced as they are against 1-wire systems (seemingly based on good science) seem to be defied by postings from owners who apparently are having good luck with the 1-wire alternators.
Any advice would be appreciated, especially if anyone has tried the 1-wire route and were forced to go back to a 3-wire system.