Recharged my magneto and truck ran perfectly. I could crank start it on mag by only pulling it through one cylinder. Took him for a drive went about 6 miles and lost the mag charge (all at once). So I am assuming that the mag is getting a dose of 6 volt from somewhere. Switch, mag wire, or what else could be the issue? I did notice that even when on mag. the volt meter was a little on the discharge side. So what to check? Thanks
There are 4 things which can cause a magneto to stop working. 1. Magnets de-magnetized. Usually caused by contact with DC voltage. 2. Open or shorted field coils. Usually caused by something in the crankcase getting caught on the magnets damaging the field windings. 3. Open connection between magneto and coil box. Such as the plug, or wire between plug and switch or the switch itself or the wire between the switch and coil box. 4.Excessive end play in the crankshaft causing the magnets to move away from the coils.
Sudden loss could be wire loose or broke at mag terminal, or at firewall terminal block.
As you saw discharge might be switch panel.
Would check the wiring at the switch if you don't know the condition of wires, and then the contacts of the MAG and BAT, if switch is old and hasn't been rebuilt.
Oct 1924 Service Bulletin