Voltage regulator appears to drain the battery

[gregb46]

I’ve had this turbo Aerovee Sonex for a few months. About 20 flights with no electrical problems. While troubleshooting the secondary ignition system I noticed the ignition modules looked slightly melted. As I replaced them (not an easy job with the engine installed) I noticed the back of the engine seemed warm.
The next morning the battery was dead. It seems it was discharging thru the voltage regulator and stator thus warming the back of the engine. I replaced the voltage regulator but it still sparks when I hook up the wires.
I can’t figure this one out. Could I have done something wrong wiring up the ignition modules?
What do you guys think???

[daleandee]

I’ve had this turbo Aerovee Sonex for a few months. About 20 flights with no electrical problems. While troubleshooting the secondary ignition system I noticed the ignition modules looked slightly melted. As I replaced them (not an easy job with the engine installed) I noticed the back of the engine seemed warm.
The next morning the battery was dead. It seems it was discharging thru the voltage regulator and stator thus warming the back of the engine. I replaced the voltage regulator but it still sparks when I hook up the wires.
I can’t figure this one out. Could I have done something wrong wiring up the ignition modules?
What do you guys think???

Greg ...

That's a tough one. If you have a wiring diagram that would be the place to start. Hopefully you have a fuse box or breakers so that you can disable various circuits while troubleshooting this. You didn't say which regulator you have installed or, more importantly, which terminal is causing the sparking when the connection is made.

Lots of folks on here are way above my pay grade on electrical wiring but I believe more information will be needed before anyone can render a comprehensive guess as to what is causing the battery to discharge. I would start by using a meter and then disconnecting items and/or connections one at a time until I located which one is causing what appears to be a short in a wire/switch/component.

If the problem is new (as it seems it is) the best thing is to go back and undo what you did before this occurred.

I know this isn't much help ... hope you get it sorted out quickly.

Dale
3.0 Corvair
Tailwheel

[gammaxy]

One possible explanation for the sparking and battery discharge over night is an internal failure of the alternator (generator) stator such that it is shorted to ground internally. You can test for this by disconnecting the two alternator leads and use an ohmmeter to see if there is a short circuit to the engine case/accessory case/ground.

I'm not sure how this would be related to the secondary ignition, though. What caused you to replace the trigger units? Even if you wired it wrong, as long as the ignition switch was off, you shouldn't have been able to drain the battery through it.