Ok after the 6.0 the light would pop up under fast acceleration no adjustment in the volts but it would pop up. So today alternater went had to push it down the street so I bought a 6.0 145amp alt. not it still pops up but like at a regular pace, after I put the new alt and charged the battery I drove bout 80miles on the highway, and it popped up once after 85mph cruise and has continued. Any ideas?

Truck is 01
Motor is 02
alt was looked up as a 2001 6.0 145amp alternator (instead of normal 130a)

 

check the battery.... whens the last time it was replaced??? also check engine, and alternator ground.

 

i think you forgot a ground somewhere

 

battery is a new yellow top, alternator ground is fine... what bout the engine? u mean the ground straps? if it was a ground strap would the truck not start?

 

i have a feelin one of the straps was bolted to back of the drivers side head, but like I siad it must be fine right? cuz if it wasnt ground it wouldnt start... right?

 

No it could still start fine..... just when charging it will start to buil a resistance..... especially at high rpm when the very sensitive recifier, and regulator are trying to figure out how much power to output.... and then it is see ing resistance..... look at your grounds..... serious

 

i just did the swap, Im sure all the ground are fine, but i will take a ganger I guess... can the be read with a scan tool?

 

1st step would be to read voltage at the battery with a dvom, then read it at alt while running... then rev some.... see how it responds... or find someone with hpt and hook it up and look at realtime data when driving

 

ill do that, but i dont know when I will be able to, as long as Im holdin a good charge am I ok? riskin anything?

 

Yes Your Risking Something... If You Have A Bad Ground And Your Alternator Is Spiking... Itll Eventually Fry All Your Electronics.... Trust Me... Seen It Before... No Good Will Come Of Leaving It Alone.... You Need To Figure It Out