Just because some of your electrical systems work, doesn't mean the battery is ok. Are the cables clean on both ends?
When you turn the key to crank, is there a load on the starter circuit? One way to tell would be to watch the dome lite or headlites, when you turn the key to crank. If the lites dim or go out, it is usually the battery or cables. Some of the national brand autostores will check your battery for free.
If the lites stay bright and there is no starter action, you may have an open circuit. If this is an automatic, have you tried starting it in neutral?
Thursday, May 29th, 2008 AT 10:50 AM