Remember that if you have a weak battery, your new Alt will work double time until you break down again...

 

Just an update. Changed the alt and ran the car for a few days with the old battery. Worked okay at first and then started acting up again. I changed the battery and so far so good. Not sure if alt was the problem or the battery or maybe both. Bottom line, my girl is running again! Thanks for all your help guys!

 

I have an 06 V6 with the exact same issue as yours. I have had the battery checked, it is fine. Had the alternator checked, It is fine. I went home took the negative lead off the battery and put amp meter in line between the negative cable and negative terminal on battery. Found that I have a 1.5 amp draw with everything off, doors closed, and no lights on. Started pulling fuses and draw went away when Ipulled the stereo fuse in engine compartment. I have the shaker 500 system. I know the stereo draws a bit of power when everything is off to hold presets and such, but 1.5 amps seems way too high. I started a new thread about this before I saw this one. Any ideas??? Do we need new stereos???

Joe

 

I'm thinking it was just the battery...

 

I had a similar issue. I would turn the key to the on position and the dash would light up, radio would turn on. Then, when I would turn it to the start position, the dash lights and radio would kill and the car would start up. About 3 to 5 seconds later the dash and radio would power up.

Since my car (05 GT) still had it's original battery, I replaced it. 5 years in the AZ heat is good for a battery. I got a new battery and it fixed everything. The car turns over quicker now as well.