after engine swap---battery light on
i have a 1999 f250 super duty 7.3l. the orignial engine was bad so i just swapped it with a 2002 engine. it started right away, ran great, the only thing i noticed was the 'battery' light was on constantly. the alternator gauge was right in the middle between 8 and 18. the truck ran fine. now after 3 starts this morning, there isnt enough juice in the battery to crank it over.
im wondering what the problem is?
the only difference i notice between the new and old engine is 1 extra wire. on the passenger side there is a thick ground wire that comes off the top of the engine (near the gpr and aih) that runs to the passenger quarter panel. on the old engine there was only 1 thick wire. on the 2002 there is also a small thin wire that i dont know what it would go to. since the new engine is from a salvage yard they just cut everything so i dont know how long the original wire was or if it had some kind of connector on the end.
any1 know what that wire would be?