Ok guys / gals, I'm new to the site so thanks for taking time to try and help me out

I have a 2006 ford Ranger 4cyl. runs great love my ranger. yesterday got in my truck and turned the key, nothing. no clicking, nothing. I jumped the battery and started right up. drove 50 miles home ran great. (with no headlights on) turned off engine, quickly tried to restart engine, nothing same issue, nothing. took the battery out and had it tested came back good (battery is only 6 months old, alternator is only 6 months old). put battery back in, tried to start it, nothing. jumped battery again started right up. turned on headlights and it died immediately. jumped battery again started right up, turned headlight on died immediately. so im thinking maybe a ground wire somewhere has a short. has anyone had this problem before? I've read some threat and seems to be several ground wires on this ranger. any help anyone can provide is much apricated. thanks in advance

 

You need a volt meter to test the system yourself
"New" just means NEVER Tested, not "it works"

Key off battery voltage needs to be 12.3v to 12.8volts
Engine running, battery voltage needs to be 13.5v to 14.5volts

If these voltages are OK then your problem will be BOTH battery cables, well one is failing but you can't tell which one

 

I figured it was along those lines. I appreciate your response I will do exactly what you recommend. thanks again

 

RonD
just wanted to let you know, problem solved. your correct the Positive battery cable was bad. im back on the road. thanks RonD

 

Good work

Thanks for posting the update AND the FIX that worked

 

Sounds like corroded battery terminals. If you "jump" the battery you are using an external source to excite the alternator field which it needs to produce current. It will continue until you turn off the engine. then you need to jump it again.
Take the terminals off the battery post and remove the carbon that formed between the terminal and the post.