VCCA Home Forums TECHNICAL - 1945 AND NEWER 1955-1957 55 Gen. Light

Since my 55 now has an Alternator instead of a Generator can the wiring (which is not hooked-up right now) be made to work for the Alternator?

Cars with alternators had battery volt gauges or warning lights becuse the alternaor DC does not work an ammeter.

I may not have asked this question quite right. My 55 now has an alternator instead of a generator. Can the wiring now be made so the warning light comes on like it did with the generator? It does not have an ammeter. It has a warning light which is what I want to work.

NO, because the alternator is always charging ( a low amout at idle) where as the geneator does not.

Gene

Shouldn't he be able to wire his warning light into the alternator exciter circuit as it was in 1963 trucks for example?

Then if the alternator stops charging for what ever reason (broken belt for example), battery voltage pushes current back to the alternator and the light lights?

(As I believe it did on the aforementioned truck.)

For the benefit of those here more knowledgeable then I,

What alternator are you running?

Just turning on the ignition with out the engine running should turn on the light.

I'm running a two wire alternator.

Alright
If I remember this right...
You will of course have the heavy wire coming off the main terminal of the alternator, which will be connected essentially directly back to the battery and thus "live" at all times.
You will also have a smaller exciter wire going to the alternator, probably from the engine ignition terminal on the key (ignition) switch.
Route that smaller wire THROUGH the generator/alternator light on the dash.

Now when you turn the ignition on, but the engine and alternator aren't running, the current running to the alternator to excite it (needed to get it to start charging as your alternator won't have a permanent magnet to form an initial magnetic field for start up) the exciter current will be lighting the light.

When the engine and alternator are running and the alternator is charging, the alternator will produce voltage at that exciter terminal which will push back against the current in the exciter wire, and cancelling it out/stopping it.
So the light goes out.

If the alternator stops charging for whatever reason while the engine is still running, battery voltage again overcomes the lack of voltage at the alternator end of the exciter wire, and current again flows through your light.
So the light comes on.

Hope this helps, and is what you were looking for.

PS
If I'm wrong here, someone please correct me and help this fellow out! :-)

Wow, you're explanation sounds great! I'll try it in a couple of days when it warms up.

I hasn't warmed up but I went out in the Garage anyway and wired up the Light Socket. Lights up with key on, goes off when Engine starts. Looks like it worked, Thanks!!

Glad to hear it! 👍