I bought a code reader for a 94 f150 5.0. It said to run a test with everything off and it came up with code 624. This prob took 30 seconds. Now my battery is dead and it's like 3 weeks old what does that code mean and what's goin on ?

 

Probably that your Battery's dead or was dieing! Codes aren't accurate w/ a weak Battery. What caused you to replace it 3 weeks ago? What do you mean "everything off"? What code reader are you using?

 

the ignition was off I mean....I bought a new battery because the truck sit awhile and it was a very old battery

 

No test without the ignition on. There are two types. Key on engine off, and key on engine running. Does it have the digital readout, or is it possible you read the blinks wrong?