(Meant to post this Tuesday, but I hit Preview and fell asleep. So here you go.)

Before I started anything, I took my multimeter and checked for the missing ground between pins 5 and 16. Should have gotten zero, instead got 11.4 volts. Did I check the right ground pin? :nm

Appeased my sanity and cleaned the (mostly shiny) cables on the top side of the engine. Multimeter shows zero resistance between any two ends. (The starter terminals, the engine block ground, and the ground under the ICM will wait for when I'm not working 13 hour days.)

However, on the drive home, I decided to turn on all the accessories while idling at a red light; I watched my volt gauge slowly slide down toward the red zone. Those random puzzle pieces of my radio sometimes forgetting the presets and the occasional hard start now seem to fit somewhere. Voltage across the terminals is 12.6 when off, around 13.5 at warm idle. Time to claim the battery's warranty?

I'm back!

Last couple of weeks: Tried to clean the ground busses, but they were spotless. Pulled out the OBD-II plug and checked the pins, and they're shiny and not damaged. Finally got around to rebuilding my cigarette lighters (after two years!) and reinstalled the fuse. Cleaned the battery cables, though there was nothing to clean off.

Had my charging system tested at Sears (who sold me the battery), and they said "all is well, give us $15." An oil change place (yes, I had a rare bout of laziness) said the battery is at 39% life and should be replaced soon. As the battery is only eight months old, either it's a lemon or my alternator is getting old.

Diagnostic port: Voltmeter reads 11.8 volts between pin 16 and the grounds. No pins are loose or damaged. Pulled the MAF sensor to set the MIL, then cleared it with my car-powered code reader. So, there's definitely power, ground, and communication.

Took it in for the free re-test, and…*it failed again! Assuming their testing equipment is working, what could be the issue? Battery cables are next in line to be replaced.

Are you able to get it tested somewhere else before dropping more money?

I could have done that from day one. But, a free re-test is only valid at the original test center. Now that I've used my re-test, I won't be back.

The shop owner says he's seen this issue before, but could never figure out why it happens.