My 1938 ford was running, with a 6 volt posi ground. And I change over to a 12 volt neg ground. I did not change the wire from the coil to the dist. Or the coil to the switch. All I did was ad a 12-6 volt reducer. On the wire between the switch and the coil. It will turn over but not start. Does not even sound like its fireing. Has plenty of gas. I did turn the switch on and notice with a test light. That I have fire on the ing switch side of the coil. But none on the other post going to the dist. Is both sides of the coil, suppose to be hot with the ing switch on, or not? Any ideas ?? I do have two ground straps grounding the motor to the frame. Also the battery to the frame THANKS !

 

never saw this setup before. did you change ENTIRE system to 12v neg ground? if so, try using a 12v coil and swap the wires on posts, (on coil). should fire right up. (even with the reducer, you still have neg ground to coil) get rid of reducer. if this does not work, give me more details on your 12v conversion.(gen, reg, switches, etc.)

 

neglected to mention that coils must match up. i do not know if you have a voltage resistor in your harness somewhere, but suspect you do.(usually on firewall somewhere). this is normally two pieces of ceramic with what appears to be a wound spring between the pieces. if you do, you need a nonresistor coil. if you don't, you need a resistor type coil. this may be marked on your 6volt coil. it does make a difference. if you wish to leave everything as is, you can try just swapping the wires on coil, should fire. i myself don't trust reducers.