Load Testing '46 Ignition Circuit
 

This question got buried in my previous post about servicing an ignition switch, so now I need some advice on testing the power supply to the coil. Thanks to one of our members, I got a NOS ignition switch. Now, my plan is to test for voltage drop in the ignition circuit. The plan is to: disconnect the coil to distributor wire, connect my remote start switch to the distributor terminal on the coil, which should equal the points being closed, connect a voltmeter to the ignition terminal on the coil, push the button on the remote switch for the time it takes to get a volt reading. As I understand it, I should get about 3 volts? Depending on the reading, I'll work my way back through the connectors, and resistor, to the ignition switch, each time activating the remote switch to load the circuit. Does all this make sense, or is there an easier/better way? The car is a late year '46 build, with the resistor up under the dash and a stock "Skip" coil.

Re: Load Testing '46 Ignition Circuit
 

I think that would work, but don't think all that is necessary. If you simply take readings at each connection point beginning at the solenoid for your base reading, you'll get good readings at each point. Devote a bit more time at the switch itself, watching your meter as you turn it on and off.

Re: Load Testing '46 Ignition Circuit
 

To test the power supply to the coil, disconnect the ignition wire at the coil and turn on the ignition switch. Touch the ignition wire to the negative jumper on your multi-meter and touch the positive jumper to the positive post of the battery (or any good ground, for that matter). The voltage should be equal or close to the battery voltage when the engine is cold. If the car's been run and the ballast resistor has heated up, the voltage should be in the 3-4 volt range.

Re: Load Testing '46 Ignition Circuit
 

If the point(s) are open, you will read battery voltage at the coil. With the points closed, the reading at the coil with the wire connected, the reading will be close to 3 volts as mentioned above. An analog voltmeter is preferable for most trouble shooting. Trying to check the voltage while the engine is running isn't possible unless you have a RMS scale.