1946 Farmall Model A Ignition

Mark1957

New User
I have a 1946 Farmall Model A tractor with original H4 ignition 6 volt positive ground. I can't seem to get a spark. I have replaced points, plugs, wires, condenser and coil. The magnito snaps as it turns. When I check the cutout terminal on the magnito assembly it shows continuity to the housing. It occurs as soon as I hook the cutout wire to the condensor? I checked the new coil and with the coil installed it has continuity with the housing assembly. Is the cutout wire of the new coil suppose to have continuity with the the metal tab on the coil that is screwed into the metal core for the coil? Any help would be appreciated. I would like to keep it original. Thank You!
 
If the points are closed or the condenser shorted it will show continuity. Yes, that
completes the circuit. If you can't get it to work, send it to me to check out. I have
a coil and condenser tester & magnet charger.
 
Before you take the mag out, check that the
rotor drive gears are in alignment.

Get #1 cylinder on TDC & remove the dist. cap.
The rotor should be pointing to #1 nipple on
the cap----plus or minus a fraction if the mag
impulse hasn't tripped.

Our A somehow got the gears out of time on
the mag, & spark couldn't jump the larger gap.
Jim
 
I double checked the gear alignment with the notch in smaller gear with the R in the larger gear since it is right hand clocked. I don't understand while so much effort is spent to isolate the lug on the condenser to then hook the cut out wire from the coil to it if that wire is suppose to have continuity to the housing? I checked the condenser and its not shorted.I checked and cleaned the points and made sure they or the wire that runs to the condenser is not shorted.
 
At TDC the rotor is at #1 on the cap just after the impulse snaps. I followed the Video on Steiner Tractor site as far as setting the rough timing. The slot that engages the Magnito assembly is pointed to the 2 &8 O'clock position before installing the Mag assembly. The only mark I could find in the Flywheel is a stamped arrow. It don't know where it is suppose to be alligned with at TDC but when pointed straight down at the ground, the eng is not at TDC. I pulled #1 plug and made sure it was at TDC on compression stroke in order to set the Mag timing at #1 cylinder.
 
I made sure the points, when open, show the condensor lug being isolated and it does but as soon as I hook the cut out wire to that lug it loses isolation from the Mag housing regardless of the points being open or shut?
 
Sounds like the kill switch is turned off. Does it spark with the wire off? Does the
switch have one or two terminals on the back.?
 
Teddy, as you well know the coil primary is in parallel with the condenser.

Even with the points "open" there is continuity from the "kill" terminal to ground through the coil primary, NO rocket surgery involved here!
 
Mark on the flywheel is next to a pressure plate bolt. It is a line with a 1 & 4 by
it. Not sure about an arrow?????
 
Am I understanding you right, the kill wire from the coil when installed, will cause the condenser lug to show continuity to the Mag housing regardless of points open or not?
 
One end of the primary is grounded by the strap & screw that holds the coil on. The
other end goes to the points along with the condenser. The moving magnet rotor creates
a current in the primary & when the points open it causes the field to collapse
inducing voltage in the secondary to produce a spark to fire the plugs.
 
mvphoto60527.jpg
This is a Pic of the Arrow on the Flywheel. I colored it with white chalk and is the V just above the starter ring in the photo. Thanks Mark
 

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