Ok so last week the battery on my truck was dead so i charged it and then went and drove it and then shut it off again and the battery was still dead. So I took the alternator off and went to napa and had it checked and the guy told me that it was shot. So I ordered a new one and installed it today and the truck still wont hold a charge and the red battery light is still on in the message center on the cluster. What do y'all thiunk the problem might be? By the way im working on a 99 ecsb with an 05 Lq4 And this problem started Right after I did the 80e swap.

 

O and By the way the battery is Only 6 months old so I really doubt that is the problem But I could be wrong.

 

Did you check the continuity of the Fusible Link wire between the alternator and the junction block?