WD alternator

The light in the wire from the ignition switch acts as a resistor to keep the alternator from back feeding the ignition system when the ignition switch is turned off and the engine is running. Your lamp may have too much resistance to get the alternator started charging. I think it only takes 10 ohms or so to be effective at allowing the engine to stop. Another alternative is a 1 amp silicon diode, like a 1N4004 or a 3 amp diode that is structurally stronger. Cathode of the diode to the alternator. This is acting like a one wire alternator set up as a 3 wire which is handy for not having to rev the motor to get the alternator to start charging. Another way to get this starting function is to replace the lamp with an oil pressure switch that has floating terminals and closes on oil pressure rise. Connect to the oil plumbing with a pipe T or whatever plumbing it takes to get the pressure to the gauge and to the switch. I don't remember the part number but I know NAPA had a suitable switch years ago.

Gerald J.

I put a one wire alt on my B and it would not rev enough to excite it.I run a wire from alt to panel and put a normal open switch on it .Now I crank and pull switch on and it starts charging and I turn switch loose and it continue to charge. It will drain batt with engine stopped if switch is in on pos .

Better grab a bunch of what you need from Radio Shack. Our local is closing. Might be over for them as I've been hearing for a while....

I use a double pole switch with one side to the alternator and one side to the coil.

I received an e-mail from Radio Shack this morning, been getting them about every three days, 60% off on all the store stock except for cell phones. I went to their web page to identify stores where I might be in the next few days and there is a notice that can be clicked on of bankruptcy. They have already filed chapter 11. Figure closing at least 200 stores.

Since the Tandy importing company bought the original Radio Shack that really knew radio going back to about 1917, Radio Shack has suffered from importitus and plain stupidity. They also bought Walter Ashe Radio in St. Louis and Allied Electronics for their retail audio stores, and instantly deleted all the domestic audio products replacing them with Pacific Rim imports. That operation went bankrupt a few years ago and the stores were taken over by a new management that has even less knowledge of radio, electronics, and electricity and the store stock reflects that lack of knowledge.

With few local stores, Jameco Electronics has 100 times the components selections. All Electronics has a fair collection and both have good online web pages. Then there are Mouser and Digi-Key that will sell in small or large quantities without a minimum order size and are near the top of the lists of big electronics distributors.

Gerald J.

I will measure the resistance of the lamp when I am at the tractor next. Does anybody have a part number or source for an idiot light that would work? Otherwise I will use the double pole switch which I have on my C, but I wanted to be able to see that the alternator is working at a glance.