Lee, I suspect this thread is fully linked to your thread on you truck not starting with it's new Optima 6 volt battery. My truck had a 6 volt alternator already installed when I bought it. However, due to the slow speed required on a lot of my rural country roads in the winter with headlights on and heater blowing it would not keep the battery charged. Problem was the alternator needed to operate at higher rpm. Well, that wasn't gonna happen and my net searches led me to install a 6 volt taillight bulb under the dash (used a old taillight socket) to act as an exciter. Now if the engine is running no matter how slow, the alternator is charging. No more problems.
I trust someone here can talk about this in detail, if I can find the info detailing exactly how to do the above, I'll post it. It's been so long ago I really don't recall the details.
Good Luck,
RonR
