Re: Alternator Question


[Follow Ups] [Post Followup] [Dodge Power Wagon Forum]


Posted by David Sherman [24.32.202.83] on Friday, August 28, 2009 at 13:41:55 :

In Reply to: Alternator Question posted by Robert N [208.57.182.24] on Friday, August 28, 2009 at 12:33:22 :

Before you get too excited about the one-wire alternators, keep in mind that under the best of circumstances, they regulate the voltage inside the alternator, not at the battery itself, so you need to make sure you have a very good connection and heavy wire. Also, in my experience you really have to spin them fast to get them to start making electricity, and on our old slow-revving motors that means making a very small pulley for them. I managed to get one to work in one of the Tuckers, but I had to "help" it by adding a wire with a diode and resistor in it from the ignition terminal to the upstream side of the output diodes on the alternator, so it's not really one-wire any more. Without that, it wouldn't kick in unless I revved the motor up way above a reasonable high idle speed, even with a small pulley.

I'm not saying 1-wire alternators are bad, just that they have their own quirks and they're not the be-all end-all solution to all charging system problems. The best thing you can do when you have a charging problem is measure the voltage at the actual battery posts with a digital voltmeter under various conditions. If you're not getting 14-14.5 volts with the motor revved up, the battery is probably not getting fully charged. Then measure the voltage between the alternator output and a solid ground. If there's much of a difference between the two measurements (more than a couple tenths of a volt) start looking for bad connections. You can test each connection by putting the voltmeter across it. If you have a mechanical regulator, take the lid off and open and close thee points by hand while measuring the battery voltage. In my experience, most charging system problems are simply worn-out brushes in the alternator, which are cheap and easy to replace, and almost all of the remainder are bad connections.



Follow Ups:



Post a Followup

Name:
E-Mail:
Subject:
Message:
Optional Link
URL:
Title:
Optional Image Link
URL:


This board is powered by the Mr. Fong Device from Cyberarmy.com