Ok its a 2001 F150 Supercrew 5.4 4x4. The truck will start but very hard to do so. It acts like a bad battery. while the truck is running I am getting 14.2 to 14.0 volts on my meter. After the truck is shut off and sits for a few minutes the battery drops down to 10.6 volts?? I can get back in the truck and if I turn the key all the way it will not start at all, but but if I turn the the jey about halfway to the full start postion the engine turns over very slowy but will start with some effort. I beleive it to be the battery again, what do you all think? The battery is only about 10 months old. I seem to be going thru a battery about every 12-15 months???

Thanks for any and all helpfull info!!
Marty

 

Bad battery. What kind of batteries are you buying?

 

Interstate.

 

Should still be covered, Get it replaced then have your alt tested for over/under charging. Also check your cables, both pos and neg at each end.