I found what I was told about the coil.
Yes the 12V coil will be OK on 6V. Another thing to be aware of, the battery cables for a 6V are bigger than 12V cables. If the cables have been changed to the small ones like so many have been, you should replace them with size 00. Check with the tractor store.
Tim, thanks for the correction on the Optima charging procedure.
A 12 volt internal resistor coil will not be OK in a 6 volt system.
A 12 volt coil with no resistor, for use with an external resistor, will be just fine in a 6 volt system, no resistor needed. If the truck was already running and starting good then this would be what you have.
A 6 volt coil, and a 12 volt external resistor coil are exactly the same thing.
Sorry to cause such a problem with suggesting one Optima battery, much less two...
It all depends on what you need, and what you plan to do with the truck.
I agree, it sounds like a cheap 6 volt will suffice for now.
But in the long run if you plan to keep a 6 volt system then I still think the Optima is the way to go, and consider buying it now to save the mostly wasted cost of the cheap 6 volt. If you live in a cold place then two 6 volts, while expensive, may be very much appreciated, or if you like overkill. And as I said in my first post on the subject, one would work just fine.
Grigg
