Mazda6--In Safe Mode/Battery Warning Light On

[SeaSpider]

I need some help...

Two nights ago, while driving my 2.3L 2005 Mazda6 down the interstate, with no warning the battery light came on, and the transmission shifted into third gear. I have one of the 'tiptronic' or speed shift automatic transmissions, but even when I switched to manual setting or slowed to a virtual stop, the car remained in third gear. When I popped the hood the next morning, the battery was misshapen and had cracked on three sides; there was acid everywhere.

So I cleaned the engine compartment, replaced the battery, and when the car cranked the battery light was out and the AT shifted fine. But only about 15 miles down the road the battery warning light flashed on again, and the AT dropped back into safe-mode.

So I plan on having the alternator checked next, but I noticed the new battery seems to be melting as well. Can a faulty alternator really do this, or is a battery running extremely hot a sure sign it's inadequately ground or there's some other kind of wiring problem in the charging system?

Thanks in advance for any input.

 

[thewheelman]

It is very likely that the voltage regulator (I think it's integrated into the alternator in the 6), has gone bad.

If you have an AutoZone, Advance Auto, Pep Boys, etc. close by, they should be able to test it on the car and let you know what the issue is.