Hi, I'm new to the forum, and I've got a quick question.
I've got a 2004 6.0 powerstroke, zero mods, zero extras.
The battery symbol came on the other day and since then I've been trying to figure out why.
I had the batteries tested at Advanced Auto, and they said they were fine, so I put in a new (re-manufactured) alternator from them. There was no change. Alternator still read around 12v when running, so I had the old one bench tested. They said it passed, so I returned the new one, reinstalled the old one, and started troubleshooting.
Here's what I've got so far:
Voltage at the alternator is same as battery voltage, and does not go up when truck is running (around 12v, but slowly deteriorates while truck is running) I have to charge the batteries overnight for them to last through the next day as I drive to work and back) yesterday voltage dropped below 9v on the way home and the truck almost shut down (lights got very dim, abs light came on, clock was flashing, etc.)
After charging the batteries (~12.6v) with key off, the orange I-sense wire reads 12.6v (battery voltage) green wire reads ~0
With key on, engine off, orange wire reads ~12v and green wire slightly less (11.9ish)
With engine running:
orange and green wires read 12.2v and 12.04v respectively
voltage at the alternator (red wire to alternator casing) is ~12.2v, same as battery voltage. (going from alternator to a ground on the truck yields same voltage)
DC current between the two batteries is 15A, current off the other red wire on driver side battery is 33A
DC current through red wire from alternator to battery reads 0.6A, and voltage drop across this wire is 0.3mV.
Battery voltage is 12.2v
Is it possible my alternator is indeed bad even though it passed the bench test? (which would also imply the brand new re-manufactured alternator form Advanced Auto was also bad out of the box)
I've got a 2004 6.0 powerstroke, zero mods, zero extras.
The battery symbol came on the other day and since then I've been trying to figure out why.
I had the batteries tested at Advanced Auto, and they said they were fine, so I put in a new (re-manufactured) alternator from them. There was no change. Alternator still read around 12v when running, so I had the old one bench tested. They said it passed, so I returned the new one, reinstalled the old one, and started troubleshooting.
Here's what I've got so far:
Voltage at the alternator is same as battery voltage, and does not go up when truck is running (around 12v, but slowly deteriorates while truck is running) I have to charge the batteries overnight for them to last through the next day as I drive to work and back) yesterday voltage dropped below 9v on the way home and the truck almost shut down (lights got very dim, abs light came on, clock was flashing, etc.)
After charging the batteries (~12.6v) with key off, the orange I-sense wire reads 12.6v (battery voltage) green wire reads ~0
With key on, engine off, orange wire reads ~12v and green wire slightly less (11.9ish)
With engine running:
orange and green wires read 12.2v and 12.04v respectively
voltage at the alternator (red wire to alternator casing) is ~12.2v, same as battery voltage. (going from alternator to a ground on the truck yields same voltage)
DC current between the two batteries is 15A, current off the other red wire on driver side battery is 33A
DC current through red wire from alternator to battery reads 0.6A, and voltage drop across this wire is 0.3mV.
Battery voltage is 12.2v
Is it possible my alternator is indeed bad even though it passed the bench test? (which would also imply the brand new re-manufactured alternator form Advanced Auto was also bad out of the box)
