Hi...early 04 6.0 i have a intermittent battery light situation.... cold or hot..tends to be on more during freeway driving than in town..but still comes on during both....sometimes it flickers on and off....sometimes sustained on and off.. NEW positive battery cable... grounds seem to be good... altenator tested at oreilys....13.4v at idle...no accs on. I just dont want to fry anything.... what should i be checking next?.... thanks

 

Ok....I bought two new Optima red top batteries. ...800cca.... battery light STILL coming on..... a couple of tests on alternator...one said bad diode..same test...says ok..... soooooo......whats next....alt?

 

That's exactly what it is. Does your truck have the dual alternator set up? My truck did the same thing and it wasn't until I replaced the top alternator that I fixed the battery light problem

 

Single set up, almost positive.........what was weird.... i was driving at night, been trying to avoid it...abit paranoid....so lights are on...battery light was not on as long as running without lights.. i did order a new alt. 185amp..... what would the differences be...between the top alt on a dual alt setup....versus the single setup alt.

 

to be honest with you i have NO idea why some trucks have one alternator and others two. All i know is when the voltage drops below (i believe my mechanic told me 10 volts) the battery light will come on. I'm sure that will fix the problem.