Charging light issue
 

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.

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.

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

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

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