87 YJ 258 (4.0 head, bunchaotherstuff, etc...)
The electrical system is stock except for:
MSD 6A box and accompanying alternator diode.
Nutter bypass, but I'm guessing that doesn't matter anymore seeing as I have a new ignition box anyway(?) and none of my emissions stuff is hooked up anymore.
When I installed my 6A the first time about a month ago, I had the run-on problem. Well, I goofed up and fixed it by using a ballast resistor. Long version of the story here
. Short story is my 6A cooked shortly thereafter and was repaired by MSD (kudos to them for customer service).
I got the box back and re-installed it about a week ago along with the diode for the brown alternator wire. The diode is installed in-line in the brown wire with the stripe on the alternator side. No more run-on problem.
As soon as I did this, I noticed my volt meter behaved differently. Usually now (but not always), when I start the Jeep the voltmeter comes up from pegged low to sit just shy of 12 volts. Sometime later it will jump up to it's normal reading of around 14 volts and stay there for the rest of the time the Jeep is running. The length of time it waits to do this varies from immediately to a couple seconds to sometime after I am trundling off down the road. Usually it does not take long. Sometimes (but not always) the jump to 14 volts coincides with a blip in the throttle, sometimes revving the motor doesn't do a thing.
I figured this was just a byproduct of installing the diode. All of it was casual concern for me until yesterday morning. Yesterday morning the battery was almost completely dead. It would give that awful anemic "bzzzt" solenoid sound, but not turn over. I couldn't even jump start it. I put the battery on the charger and it easily took a full charge and started right up. The volt meter continues it's antics.
It kind of behaves like I am leaving a really small light on, like a super-slow drain on the battery. But I have not left any lights on and the installation of the 6A and diode are the only things that have changed about the electrical system recently. These changes also exactly coincide with the new behavior.
Any particularly likely places I have hosed this up? Anybody else have any similar experience?