The Stovebolt Site Forums The Shop Area The Electrical Bay Idiot Light for 1-wire Alternator

I recently replaced the generator/regulator setup on my '61 Apache 10 ('Mater Jr.) with a 1-wire alternator. I take satisfaction in making original technology work as intended; the generator worked fine, but the voltage regulators I bought would last about 4 months, then start acting up. I'd take both components to an automotive electrical shop for tests: generator=good, regulator=bad. The last regulator I bought was a genuine 'made in USA' Delco, but it didn't last as long as the offshore ones. This sort of swap has been covered extensively elsewhere, so unless someone posts questions, I won't bore you with those details.

I wanted to keep the function of the original idiot light, and didn't want to install an aftermarket voltmeter. I bought some different electronic modules online, to experiment. The common issue is that they want to activate the warning light at approximately 11 volts. That's not a 'charging' light, that's a 'low battery' light! If you're running an electronic ignition (which I am) or a fuel injection system (which I plan on installing), 11 volts is way too late. By then, your cranking voltage may be too low for reliable operation of the electronics.

I ended up using an American Autowire 11-volt sensor module, available at multiple online stores for about $30. With the addition of a few inexpensive components, I am able to easily trick the module into activating at 12.4 volts or 13.3 volts. Another reason I liked this module is that it uses two separate wires to power the indicator, so whether you're using incandescent bulbs or newer LEDs, this module will work.

I like the results so much, that I have another module to install in my '60 Impala (the PO installed a 'cool' set of below-dash aftermarket gauges, including a voltmeter), to get its idiot light working again.

-Kevin