this is very good observation... the voltage drop may be primary cause to the issues, as the drop causes the module to lose its "footing", or, the drop could be secondary - something causes a sudden load on the current and the voltage regulator drops the voltage... the second version should not be happening, as the voltage regulators are designed to prevent that from happening by holding up the voltage upto the nominal current of the alternator, which is 150 or 180 Amps... i don't think you had a sudden rush of current through the system (fuses would start popping!!), so the chances are the voltage regulator/the alternator should be replaced...

on the other hand, considering that the onboard voltage monitoring is somewhat buffered, if you saw 11.8v drop, the real drop may have been much lower (which makes me look at the battery with a suspicion - internal resistance drop inside a faulty battery may create some current issues, as entire electrical system of the car goes through a single point - the battery)

Battery is brand new.

i bought a brand new battery manufactured in August of 2013 that measured 12.5 VDC and 1115 CCA (nominal 12 V and 900 CCA) out the door on September 30, 2013... on October 30, 2013, i returned that battery with 700 CCA and voltage that would not go higher than 10.48V sustained - less than a month old battery was defective from the get-go... one of the internal chambers must have been compromised...

just a thought... :)

I will test the battery in the morning. Cant hurt and if it ends up saving me from having to swap an alternator again I will be happy. Battery has just over 12v after sitting all night though. So I doubt im that lucky.

here is a snap-shot of the battery info from the advanced-auto parts reader...

it is not just the voltage that you need, it is also the internal resistance, that is usually is not measured by a voltmeter but can be "deduced" by a "under-load" measuring...

the car's electrical system is "rated" around 2,000 -2,500 Watts, and all of that current goes through the battery, about 150-200 amps max, about 80-100 amps sustained... that is a lot of amperage (1 amp is enough to kill a man!!)

so, be careful around the battery...

I know exactly what you're talking about, know how to test a battery.

I just wish this car's electrical system wasn't as sensitive as a woman with PMS.

Just swapped in a replacement alternator. The first one was jumping between 13.5 and 14.1 volts at idle. It would drop to 11 or so after being at 2000 rpm for a bit. The new replacement sits 13.9-14.1 at idle and pretty much holds steady at 13.9.

Hopefully the replacement reman holds up this time.

I'm sorry I didn't see this earlier. I had the same issue last year while pulling a uhaul so I figured it must have been related to that. After researching decided to change ignition switch and problem has been gone. Had a lot of people pushing me towards battery/alternator but fortunately much cheaper and an easy DIY.

Scott

New alternator is charging like a champ, but it sounds like a low psi supercharger. Looks like i get to order another replacement.

Got a refund from the first parts supplier, ended up going to Carquest and getting a reman, so far it's working like a champ and isn't making a peep. Hopefully it lasts. If this one dies I'm just ordering a brand new OE one.