1942 M Ignition switch resistor

jb999

New User
I have a newly acquired 1942 Farmall M - 1942. Original 6 volt system with generator. It has a Push/Pull ignition switch that is powered from the Fused box (Light/Generator output) switch. However, there is a resistor? that the line runs through on the way to the ignition switch. (See Attached Picture). Issue is that the 6 volts turns into 4.3 volts after going through this resistor to the ignition switch and therefore I'm only getting 4.3 volts at the coil. [b:d865ca1d77]Can this resistor be eliminated?[/b:d865ca1d77] What is its purpose?
I'm having starting issues - very weak yellow spark. Only way I have been able to get it running is by pulling it. I have not seen this setup mentioned on the ignition related posts I have reviewed. Have new points, condenser and rotor on order.
Thanks for any advice on this.
 
You do not want any resistor in the circuit with a six volt system. Full battery voltage
to coil.
 
(quoted from post at 08:11:05 07/24/16) I have a newly acquired 1942 Farmall M - 1942. Original 6 volt system with generator. It has a Push/Pull ignition switch that is powered from the Fused box (Light/Generator output) switch. However, there is a resistor? that the line runs through on the way to the ignition switch. (See Attached Picture). Issue is that the 6 volts turns into 4.3 volts after going through this resistor to the ignition switch and therefore I'm only getting 4.3 volts at the coil. [b:5fec1f7577]Can this resistor be eliminated?[/b:5fec1f7577] What is its purpose?
I'm having starting issues - very weak yellow spark. Only way I have been able to get it running is by pulling it. I have not seen this setup mentioned on the ignition related posts I have reviewed. Have new points, condenser and rotor on order.
Thanks for any advice on this.

The only resistor I know of located in that box is to allow for bright or dim headlights. The ignition wire is not supposed to go through that resistor. Most likely someone was in there before you and got it wired wrong.
 
this resistor is mounted next to the ignition switch - my picture didn't upload too large I think - will retake at lower resolution.
Not sure why this resistor is here?!
 
(quoted from post at 10:27:10 07/24/16) Looks like someone was running it on 12 volts before. What bulbs are in the lights?

If it was 12 volts before, the resistor is necessary. If you are going back to 6 volts, you can get rid of that resistor.

There a few different headlight bulbs that are for use on 6 volt systems. #1133 is one of them.
 
First posters are prevented from posting pictures for forum security. Kids read our posts, and some nasties are out there. You can ask Kim (Feedback forum to
the left) If it is 6v it does not need that resistor at all. Jim
 
Could very well have been run on 12 volts @ some point in time.
6 volt bulbs are in the headlights.
The voltage regulator which sits on top of the generator is labeled as 12 volt and looks relatively new.
There is a 12 volt coil with a ballast resistor between it and the distributor.
It is still a positive ground with a new 6 volt battery.
 
You will need a 6v regulator, and if the generator has the original tag, and it is black, you are good to go. if was originally red it is probably a 12v
generator. Jim
 

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