Is there any way to provide a test signal to these....I have a great original, but it jumps all over the place when connected to my Pertronics ignition, even with the proscribed 10,000k resistor in line. I have seen on some sites where a small circuit comprising of a resistor and a capacitor (which may dampen the peaks (?)) is constructed...may try that, but if I sell mine on eBay to get another I would want to ensure it is in fact working to at least a points set up....
My orig is a two bulb...I wonder if it is indeed original???
