I had recently replaced a bad Mitsubishi alternator which was not providing power smoothly. Later its voltage regulator got fried or what and it started overcharging. Blew my high beams and dried out my new AGS battery.
Got a used Denso in place of old one. I think Honda has put both brands of alternators.
After the swap, the charging voltage at the battery was at 14.1 volts. The ground cable looked in a bad shape to me. here is the condition
It goes from battery negative to chassis and then to engine. The battery terminal has been removed from the cable in the pictures.
The peeled off section of the cable is genuinely like this to sustain the vibrations of the engine.
I had a audio power cable lying around. The thick red cable used to power up the amplifier.
I used this cable to remake similar cable using the same center terminal.
After installing, the battery voltage at idle dropped to 13.7 volts. This was disappointing for me. I drove for a day or two like this but no improvement.
Then i went to remake the positive terminal and clean the alternator out connection. The alternator thimble was blackish, needed some fine filing and sand paper to look like new. The positive terminal was also in bad shape. Clipped the ends of the cable and cleaned the contacts. Also i soldered the ground cable clamps to get good electrical connection.
You can see the engine ground terminal in the back.
RESULT: After doing all this, the battery voltage at fast idle went to 14.37 and after warming up it stabilized at around 14.2 volts. This was a relief.
Conclusion: Keep your high amp connections in top notch condition for healthy operation of battery, alternator and all electrical equipments.
Hope that this helps old cars owners and those having electrical issues...