100 AMP alternator Q&A
You don't need a resistor, all you need is a diode. I used to run one of these not long after they came out. Hook the no2 terminal to "sense" (battery) and no1 is keyed power through a diode. You want the band of the diode like in this internet photo I scammed (photo at bottom of post)
To the OP if you DO upgrade alternator amperage, a couple of things: Do NOT put a great big alternator on the car without changing the poor factory wiring situation. Read this article at MAD electrical
http://www.madelectrical.com/electricaltech/amp-gauges.shtml
and by the way at least part of your problem might be poor headlight wiring, highly recommended to add headlight relays. Crackedback on here is selling a kit
You can easily convert your factory ammeter to a voltmeter, see this thread. Read all three pages, as it covers several different instrument cluster styles
http://www.forabodiesonly.com/mopar/showthread.php?t=119480&highlight=ammeter+conversion
It is also important to understand that bigger amp numbers are not always better. All alternators (if you can find them) have performance curves which show maximum output current versus shaft RPM. There are some 40-45 amp alternators that put out BETTER at low RPM than some of the HIGHER rated alternators!!!
Generally, "more modern" is better. You at least need a Mopar "square back" instead of a "round back" and a lot of guys have had good luck with the modern Denso units.
Earlier, undesirable "roundback" unit at right, newer, desirable "squareback" unit at left. It is IMPORTANT to understand that roundback units came BOTH in pre 70 (grounded brush), in 70/ later (two isolated brushes) and CONVERTED units which were hack jobs by rebuilders, converting older grounded brush units to newer isolated brush. These are often but NOT correctly called "dual field."
You don't need a resistor, all you need is a diode. I used to run one of these not long after they came out. Hook the no2 terminal to "sense" (battery) and no1 is keyed power through a diode. You want the band of the diode like in this internet photo I scammed (photo at bottom of post)
To the OP if you DO upgrade alternator amperage, a couple of things: Do NOT put a great big alternator on the car without changing the poor factory wiring situation. Read this article at MAD electrical
http://www.madelectrical.com/electricaltech/amp-gauges.shtml
and by the way at least part of your problem might be poor headlight wiring, highly recommended to add headlight relays. Crackedback on here is selling a kit
You can easily convert your factory ammeter to a voltmeter, see this thread. Read all three pages, as it covers several different instrument cluster styles
http://www.forabodiesonly.com/mopar/showthread.php?t=119480&highlight=ammeter+conversion
It is also important to understand that bigger amp numbers are not always better. All alternators (if you can find them) have performance curves which show maximum output current versus shaft RPM. There are some 40-45 amp alternators that put out BETTER at low RPM than some of the HIGHER rated alternators!!!
Generally, "more modern" is better. You at least need a Mopar "square back" instead of a "round back" and a lot of guys have had good luck with the modern Denso units.
Earlier, undesirable "roundback" unit at right, newer, desirable "squareback" unit at left. It is IMPORTANT to understand that roundback units came BOTH in pre 70 (grounded brush), in 70/ later (two isolated brushes) and CONVERTED units which were hack jobs by rebuilders, converting older grounded brush units to newer isolated brush. These are often but NOT correctly called "dual field."