If you feed the plug 1.3 to 1.7 volts you will see a larger current swing. Because of the larger current swing, that is what is monitored on most control panels. Not voltage.





the current swing that you speak of I assume is the equivalent to current draw which you are correct in seeing as amps , the current fed is volts and most of the standard glow plugs are of the 1.5 volt type , they will however with stand more voltage than rated to a point , before they burn , which was my warning to cheesyD ,nothing more nothing less.

want to try for yourself turn the knob to deliver maximum Voltage to the glow plug and hook it up to your plane ,

Highlander