Battery light on, dead battery
 

On the way home last Friday, battery light came on, while on the way to my friends house. I told him of my light and he gave me a voltmeter to test the battery while engine was running. Only 11.00 VDC. He said go home right away and don't stop for anything, even gas. I got home safely, but had to prepare for a weekend trip to visit colleges for my daughter. Came back sunday and the battery was completely dead and the frunk switch did nothing at all. I figured I drained the battery on the way home. I connected my Porsche Charge-o-Mat Battery tender through the cigarette lighter port and what do you know, about 5 minutes later I was able to open the frunk and trunk. Once I got the frunk opened, I connected my heavy duty charger/starter to the battery and put the top into service mode.

Turned out to be a bad Voltage regulator, replaced that and also the serpentine belt.
Not to bad of a job. I pounded on the tensioner bolt for about half an hour and finally got it loose. The rest of the job was easy.

The tensioner pulley bolt is not supposed to be loosened to replace the belt. The pulley is on a torsion spring, so you're just applying pressure to relieve the tension on the spring.

Anyhow, nice work diagnosing the regulator ;)

Sorry, I misspoke, it was the idler pulley next to the alternator pulley that I used a punch and hammer on, not the tensioner pulley. I used the 24mm socket on the tensioner pulley. :p

I did this job on mine a few months ago. Had a bear of a time getting the alternator back in until I had that "duh!" moment to knock the bolt insert farther through the housing. :o ;)

Yes, it was real tight in there, probably should have listened to the experts here and taken the passenger side seat out to get room in there to work around. Live and learn.