|
|
Posted by Sheman in Idaho [72.47.153.24] on Wednesday, June 06, 2012 at 22:36:21 :
In Reply to: Re: 12 volt coil used in a 6 volt system ??? posted by Kaegi [24.16.253.154] on Wednesday, June 06, 2012 at 22:17:46 :
In a 12 V system with a ballast resistor, the starter relay usually bypasses the resistor while cranking. So, while running, you're correct, but while cranking you get an extra boost, which helps because the starter motor pulls the battery down by several volts even in a strong system.
The ballast resistor is there not so you can use a 6 volt coil in a 12 volt system, but so you can bypass the resistor for an extra boost while cranking. On one of my trucks, a 12 volt M37 with a foot-pedal starter, I wired a manual "ignition boost" switch that bypasses the ballast resistor. It made all the difference in the world for cold weather starting. The foot pedal doesn't provide any easy way to automatically bypass the ballast resistor, and by having a manual switch, I can keep the boost on until the engine warms up a little bit if it's threatening to stall.
Follow Ups: