alternator/battery dead or short?

[E-rock]

so yesterday i took my truck out for a quick test drive to check out some dirt roads in the pasco area in florida near my school and everything went just fine and dandy so i return to school and park in the parking lot. an hour later me and some friends go out for a beer run to the gas station and the explorer wont start. the head lights dim and then turn off as well as all the interior lights in the car until i take the key out, and then the interior lights turned back on because the door was open. i had my friend jump the car and it started after a few hard turns. on the way to the store the lights were flickering, so i think its the alternator. at first i was bangin on the starter thinkin that was it. anyone have any ideas?

 

[btexpress]

charge and test the battery, check the alternator output with a voltmeter.

 

[E-rock]

how much voltage is weak and strong signals from the alternator

 

[manaen]

when your alternator is working properly you should maintain around 14volts while the engine is running

and the battery on a full charge should be around 12.5 volts

 

[E-rock]

cool thank you for the speedy responses