Charging issue '70 Swinger
I'll try to give as much detail as I can. Charging systems have always been my weakness.
1970 Swinger 318 with a two field alternator. My dash ammeter started dropping to discharge always at idle. Approaching a turn, my turn signal would make the needle wave back and forth between charge and discharge. If I turned the lights on while driving it would drop to the center line. I checked the voltage at the battery and at idle it was about 11.5 volts and at higher RPMs it was just over 12.
I replaced the alternator which to be honest looks like the original old style alternator with a 1969 date stamp on it so Im guessing maybe it had been rebuilt and repaired previously as opposed to being replaced. I replaced it with a 60 amp alternator from NAPA and also installed a new NAPA voltage regulator. I put a new end on one of the field wires which had some frayed strands. The odd thing is that since owning the car I could never figure out what this shiny goo was dripping down the firewall. It turns out the resin or whatever it is filling the backside of the old regulator was melting and dripping. Anybody ever seen that before? Maybe typical but its the first for me or is this a sign of other problems. See photo.
Now that Ive replaced those two components, the ammeter sits just a hair above the centerline at idle and moves up to the first charge line at any higher RPMs. It lowers about a needles width towards center when the headlights are on. And flutters into discharge at idle with the headlights on and a turn signal on. As long as Im above idle its always up near that first charge line. See photo.
I checked the voltage of the battery and it was 12.68. At idle it dropped to 12.62. I ran up the RPMs and it jumped to 13.02 and then did a digit-by-digit slow creep up to 14. Headlights on and it slowly dropped to 12.83 at higher RPMs and 12.57 at idle.
After that idle was 13.31 with the headlights off.
I swapped to a second regulator from my sons project car and it replicated the first results.
Is this a bad new alternator? Bad battery? Maybe grounds? Bad dash ammeter? What should I be testing here? Am I about to fry some wiring or the battery with the apparent constant state of charge or is this just the quirkiness of a 1970 charging system?
Thanks.
I'll try to give as much detail as I can. Charging systems have always been my weakness.
1970 Swinger 318 with a two field alternator. My dash ammeter started dropping to discharge always at idle. Approaching a turn, my turn signal would make the needle wave back and forth between charge and discharge. If I turned the lights on while driving it would drop to the center line. I checked the voltage at the battery and at idle it was about 11.5 volts and at higher RPMs it was just over 12.
I replaced the alternator which to be honest looks like the original old style alternator with a 1969 date stamp on it so Im guessing maybe it had been rebuilt and repaired previously as opposed to being replaced. I replaced it with a 60 amp alternator from NAPA and also installed a new NAPA voltage regulator. I put a new end on one of the field wires which had some frayed strands. The odd thing is that since owning the car I could never figure out what this shiny goo was dripping down the firewall. It turns out the resin or whatever it is filling the backside of the old regulator was melting and dripping. Anybody ever seen that before? Maybe typical but its the first for me or is this a sign of other problems. See photo.
Now that Ive replaced those two components, the ammeter sits just a hair above the centerline at idle and moves up to the first charge line at any higher RPMs. It lowers about a needles width towards center when the headlights are on. And flutters into discharge at idle with the headlights on and a turn signal on. As long as Im above idle its always up near that first charge line. See photo.
I checked the voltage of the battery and it was 12.68. At idle it dropped to 12.62. I ran up the RPMs and it jumped to 13.02 and then did a digit-by-digit slow creep up to 14. Headlights on and it slowly dropped to 12.83 at higher RPMs and 12.57 at idle.
After that idle was 13.31 with the headlights off.
I swapped to a second regulator from my sons project car and it replicated the first results.
Is this a bad new alternator? Bad battery? Maybe grounds? Bad dash ammeter? What should I be testing here? Am I about to fry some wiring or the battery with the apparent constant state of charge or is this just the quirkiness of a 1970 charging system?
Thanks.