By E. Meloan
(This article was originally published in the July, 2003 issue of the Spark Coil.)
In our last column, we continued our discussion of the electrical system of the Model T. We mentioned problems associated with the magneto. Now let’s talk about recharging the magnets in the Ford Model T magneto system…
Success depends on several things. The condition of the magneto coil windings, the gap between the magnets and the magneto coils and the care with which we align the magnets when we attempt to charge them.
There is no question that getting freshly charged magnets from a Model T parts supplier or individually recharging your old magnets when the engine is apart will usually offer a more reliable method of getting a strong magneto output. This is the way to go if you are rebuilding your engine anyway. But if the engine is in good mechanical condition and the magneto is the only problem, then it may be worth considering a recharge effort. One other comment before we go ahead with magneto recharging… The modern distributor setups sold by the T parts suppliers do not need the magneto! The distributor will work quite well using a six or twelve volt storage battery and will eliminate the need for the magneto and four spark coils.
Still interested in a magneto recharge? OK, let’s get started. The first thing we will need is a good strong source of current. Two 12 volt car batteries will serve nicely. We will want to hook them up in series to get 24 volts. We will need heavy cables to carry the current. Two sets of jumper cables will work for that. Half of one set will connect the negative post of one battery to the positive post of the other battery. The other set of cables will be used from the batteries to the car.
We will also need a compass. The compass will allow us to line up the magnets with the coils as shown in diagram 1. Your success will depend on how accurately you line the magnets up with the coils! Care used here will help get the best results. Position the car so that it points east and west then place the compass 1 inch behind and 1 1/2 inches to the right of the magneto contact on the flywheel housing as shown in diagram 2
When the flywheel is positioned correctly the north seeking portion of the compass needle will point to the front of the car. Moved to the left hand position, the compass will point to the rear of the car.
Connect the cable from the negative post of the batteries to the magneto post. We want to make our contact with the positive cable to the flywheel housing to lessen the possibility of damage to the magneto post. Now, firmly touch the positive cable to the housing and hold it there for 2 or 3 seconds. Do not hold longer! It is the initial jolt that does the work! Holding it longer can damage the coil windings! Best results will be obtained by repeating the contact several times.
NOW turn the crank to move the flywheel 1/4 turn and line up the magnets with the compass again. Repeat the contacts at the new position of the flywheel. Do this every 1/4 turn until you are back at your original position. That’s it! More details can be found in Murray Fahnstock’s excellent book “The Model T Ford Owner” available from any T parts supplier.
See you down the road…