WABBMW wrote:Sorry if I did not explain very well. The readings were with the key in the ON position, otherwise there would be no coil voltage to measure. So, with the engine stopped, and the ignition switch ON, the headlight and parking lights are ON, and the voltage decreases from the 12.5 down to 11.7 due to the draw of the lights. Is this normal?
As Bounty said, considering you have a dyna S, that's not a bad drop at all. Obviously less is better, but with that much current, the main fuse alone could drop near that much.
One thing I noticed about the regulator failures is that they can go gradually. I've had at least two that appeared fine when testing parked, but it wasn't til I ran with a voltmeter attached that I noticed the voltage dropped slowly at a steady high RPM. At around 6000 RPM i watched the voltage go from 14v down to 11 over about a half hour on the highway. Then stopped to idle and it climbed back up. Revved it alittle and it was back to 14v. Got back on the highway and same thing... dropped slowly back down to 11. New (used) reg/rec and the problem was fixed.
You want to try to rig up some voltmeter to the tank and give it a glance on a nice long highway run and see if yours is doing the same thing.
I designed a few idiot lights too if you are into building simple circuits.
Single LED adjustable version
Three LED version
