Charging light issue

[pfarah]

So... I've been having some problems the last couple of months with my 84 running a bit rough at times. Idle would be @200-250 rpm lower than normal and, very intermittently, she would cut out while driving at speed. I've noticed that the charging idiot light would start to glow brighter as I turn on more loads (rear defrost, fog lights, etc.). I performed a series on voltage tests and found, under load, the voltage was about 11.5 vdc. This would happen at all ranges of engine speed so I determined that my voltage regulator was faulty. I removed the alt., found that the unit was pretty bad so I installed a new one yesterday. The car is now running beautifully, no more hesitation, hiccups, and the idle is actually perfect. The voltage at the battery is 13.4-13.5 vdc when running with or without any loads. I drove about 40 miles and not a single problem except for this: My charging idiot light still glows faintly when I turn on loads while driving. Is this something to be concerned about? Thanks for any input.

[Tom944]

It's possible that your battery is failing due to the old alternator, it could be continuously drawing a lot of current. Turning on other electrical stuff would then make the light glow. Worth getting he battery tested.

[Kevin.]

What is the voltage now under load with the new regulator?

[Mrmerlin]

did you replace the brush holder with a Bosch part or aftermarket?
if aftermarket parts were used i would suggest to use Bosch parts

[pfarah]

Thanks for the replies. I actually replaced the entire alternator, which included the proper Bosch regulator. The alt part #: AL29X. With the newly installed unit, I am getting 13.4-13.5 vdc under all load conditions. Tom944, you may be right with regard to the failing battery. It's only one year old and I am vigilant with maintenance (water levels checked frequently and only distilled water used). Perhaps the low alternator output has caused the battery to become weak. It's an Interstate battery however; I'm not thrilled with the maintenance type. Should I look into an Optima or similar sealed battery style? I welcome any suggestions.

Patrick