The Battery light came on in my truck it will start even after sitting all night is idoling really high

 

Moved to the 1997-2003 F150 section.

 

Hello Denver and welcome to FTE!

If I am not mistaken, the battery light being illuminated indicates a charging problem. This is like the alternator light in older vehicles. It may be starting now but pretty soon it may not. The high idle could be a IAC or TPS problem. Take it and have the alternator checked out. Good luck.

 

Just start it and pull the postive off the battery. If it shuts off, this tells you your truck is running off the battery and the alternator is bad.

 

Not the best advice. The battery provides a filtering effect on the electrical system. Removing the battery from the alternator will unload the system and can have very detrimental effects on electronic devices in the truck.

 

Boy that's the truth! You NEVER want to remove the battery cable while a vehicle is running. This was a common practice BEFORE computer controlled engines to see if the alternator was working. Try that on a newer auto and you will fry the CPU. Take the truck to Auto Zone and they will check the battery/charging system for free.

 

Sorry for the bad advice. I guess I'm just old school. Thanks for straightening that out fellas before I caused somebody to damage their truck including me.

 

Indeed! Modern Alternators monitor battery voltage & need the 12 volt input to operate properly. Any Autozone, Oreily's, Advanced or other chains will test your charging system for free because they hope to sell you the parts to fix it. If your not capable of replacing parts Then chains like PepBoys will do installs & Those like AZ & ADV will normally have a local shop or 2 they recommend.

 

Sounds like it's not charging to me. Better get it tested before you get stranded.