Originally Posted by GUITAR1989
. my batt is at 11.## volts with key in off position but when i put the key in the on position voltage drops fast to like 6 volts
Sounds like you either have a massive draw (unlikely) or the battery is shorted. A good battery should read 12.4v or higher alone, and stay well above 12v for quite a while with the key on.
A few things to try:
1 - disconnect the negative terminal. Use a multimeter to measure the amperage between the disconnected cable and the negative post. Do the same with the key on and off. If you have anything more than .25 amps, you have a drain.
2 - disconnect the negative and put the battery on a charger overnight. If you test it in the morning and its below 12v, the battery is toast.
3 - If you have more than .25 amps after trying #1, leave the meter in place and pull and replace fuses one by one. If (for example) you pull the "wiper" fuse and the amperage drops significantly, you have narrowed your problem down to anything on that circuit. MUCH easier than guessing.
4 - use a known good battery and try to start it. If it doesn't start, suspect the starter. If it does start, test voltage while running. If its not above 14v, you may have a bad alternator.