Do I need an alternator?

[Paul from Maine]

Went to the car show at Amherst NH and picked up a couple of old, used plow headlights. I drive a lot at night and, though the stock headlights were OK, I really wanted more light. So I bought a couple of 6 volt sealed beams at NAPA, put them in the plow lights and bolted the plow lights on the headlight bar (it was like they were made for a Model A!?). I love them! They look good and give as much light as these new halogens that come on late model cars. Only problem is that they draw 16 amps. How many amp hours are there in a typical group 1 battery? The car runs fine with such a heavy draw, but am I straining the battery or the stock generator? The Ampere guage shows a charge of 9 amps at high idle with no load, but turn on those headlights plus the taillights and the dash lamp and it drops way down to a steady 15 amp discharge even when cruising. So do I need an alternator? I kinda like my generator. I don't want to increase the generator charge rate cause I think that'll raise the voltage and burn out my nice new sealed beams.

 

[Mike V. Florida]

Get a regulator for the generator. There are 3 types available, one that replaces the cutout, one that replaces the band, and one that replaces the third brush.

 

[MikeK]

The A generator gets mighty hot at a constant total output exceeding 12 amps, but will do 18+ for short periods. If the pair draw 16 amps @6V, the bulbs are about 50 watts each, a bit much for a genny. Replacing the third brush with an EVR will help keep the voltage in a safe range if you wish to keep the genny and use those lamps for short runs. If you use the generator as a 12 volt, two 55 watt/ 12volt halogens will draw only 11 amps. Not much of an answer, just some facts.

 

[steve s]

I too kind of like the looks of the sealed beam buckets on my Ford. They were there when I bought it in 1960 (photo below) and I decided to keep them through the restoration (avatar photo). Don't know what they're from.

I defer to MikeK regarding what the generator is capable of but I can tell you that I fried two of them before I upgraded to a jerry-rigged Delco 6V regulated system. Even then, it was a struggle at idle or low speeds. Total brown-out if I was driving at night with lights, heater, and radio on, and then had to hit the brakes and horn--just a soft grunt in the dark.

I'm pretty sure that you don't have to worry about too much voltage if you slide the third brush to raise the current output. But, it will cook itself (I remember a black, charred mess) if you step up the output and don't use that output, like by driving with lights on during daytime. Ultimately, I converted to 12V and alternator, with a song in my heart.

Steve

 

[Aerocraft]

The ammeter is already answering your question. The stock generator will not sustain the load of the lights. An alternator is a very easy fix. You also might want to consider running heavier wires since the draw very well may be too much for the stock wiring. Switching to twelve volts would negate the need for a wiring change. Gar Williams

 

[Ice man]

You are so border line, and that kind of set up would be a brease for an altinator. And you are not really changing much, so if you want to show it with stock stuff, that can take 15 mins and you are back to stock. I like mine and even went for the NEW volt meter from Snyders, and thats a lot better for me, and no worry about heat and damage at the amp meter. Iceman