[Jbird_11]

Need some help guys drove my truck home the other night from work went to tim Hortons turns truck off to order then fired up went home ate then went to bed woke up the next morning and the truck was completely dead no power to that battery’s so went to jump it and it acted like something is grounding out so looked for melted wires found nothing obvious with out ripping it apart then I unhooked the alternator and the starter I case those are shorting and still nothing

ps the truck won’t take power at all even when u boost it or quickly hook the battery’s upno lights or nothing turn on and seems to drain the battery’s super quick

03.5 f350 6.0 with cold air, red neck straight pipe, edge tuner

 

[Hydro]

Charge the batteries with the grounds disconnected and would be a good idea to have them tested for capacity
How old are they? possibly just died of old age, if the alternator is not charging good

There are a few scenarios that would explain your situation, but best to start with hot batteries first

 

[Jbird_11]

I charged them already and one I think is grounded out and busted and it’s still does it even if I don’t have battery’s in it and just hook cables up from another truck so idk what’s going on

 

[Hydro]

Be sure the doors are closed first -- there will be some current draw when first connecting the cable, but not much
this is because the electronics need to go into sleep mode, this takes a few minutes
if the door is open then the cab lights will pull some current

Best to test each battery out of the vehicle with an old fashioned load tester -- tho some of the new fangled testers work, I have seen mixed results

 

[Pyro-z]

I've seen diodes short inside the alternator and draw the batts down overnight. Normally you can hear it hum with the key off. The 4 gauge red wire connected to the drivers side battery feeds the fuse box (so basically everything) on the truck. Try hooking your jumper cables just to that 4 gauge and ground. If you don't have lights etc then its something with that wire or the cjb (fuse box).