So i finally swapped in the 6.0 and it ran to the car wash, back to the house, and for a littlefun test drive, but now nothing. Its acting as if the battery is dead, but the batt is reading 12.8.

Tested the starter and alt...both good. Got the batt tested and it came out good as well. Been going through checking grounds but all seem to be where they should. Anyone ave any ideas???

Im stuck.

 

No one?

 

Does it crank or does it not even turn over?

 

It tried to crank then it clicked as if the batt were dead

 

if you are getting 12.2v on a volt meter while the truck is sitting then you need to hit the key while someone watches the volt meter to make sure that it's not dropping below 10.9v if it is then change the battery. if its doing fine but not starting still, THEN:


jump the starter at the fuse box.
pull the starter relay *make sure you put it back the same way* jump 87 to 30 if it still does the same thing then you need to pull the starter and put a ground to it then 12v to it and jump it with a wire from the ign to 12v while the starter is in a vice.

 

Definitely what he said ^^^^^^^^^

 

My bet....loose ground. Mine did the same thing way back when. Turned out the big ground from the battery to the front of the engine block came loose.

 

Not to sound completely stupid if none of those above options don't work... Did you put oil in it?! Motor possibly seized or would the low oil sensor catch it before that?! Just curious.

 

So...i went through and cleaned the grounds and hooked it back up and BOOM! Fired right up.

 

Glad you got it figured out man.. Rather loose grounds than engine trouble.