05 Electrical Fun, Battery Meter pegs high, Alt fails voltage test

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Wanderfloof

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As the title says, I'm having some funky electrical problem. My alternator fails at 12.11V, engine around 2-3k rpm and 12.13V when idle. However my battery meter is pegging up to high and throwing the check charging system warning. Currently I'm checking the ground connections to see if they're the culprit. Battery is still strong at 12.3V under load(headlights/climate fans in a middle range, car off), going to check unloaded voltage. Any other ideas?

I am going to re-run the alternator test after checking and securing/redoing any loose/bad grounds. If it fails after that, I'll pull the alternator and get it bench tested.
 
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Yupster Dog

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I'll pull the alternator and get it bench tested.
You can get the alternator tested on the truck at Auto Zone.
Good idea checking the ground and wires. You can make sure the connections and wires are good without the work by doing a Voltage Drop Test.
 
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Wanderfloof

Wanderfloof

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Are you the original owner ? Is it the original alternator ?
Not the original owner and definitely not original alternator. It has a remanufactured sticker on it.

You can get the alternator tested on the truck at Auto Zone.
Good idea checking the ground and wires. You can make sure the connections and wires are good without the work by doing a Voltage Drop Test.
I have the code reader that runs the alternator test with the alternator in the truck and that's where my numbers came from. Does a alternator (while running at 2k) or a battery voltage test.
Haven't had time to run a voltage drop test. Been a bit busy with life stuff. Any suggestions on running it?
 

Hamfisted

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Ok, when you replace the alternator, use one from a NAPA dealer or a Motorcraft unit from Rock Auto. Unless your Expy came with factory navigation you have a 110 amp alternator. Replace it with a 110 amp alternator or the ECU will get emotional and trigger the charge system warning lamp. Don't buy an alternator from freakin Advance Auto .






.
 

whtbronco

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Ok, when you replace the alternator, use one from a NAPA dealer or a Motorcraft unit from Rock Auto. Unless your Expy came with factory navigation you have a 110 amp alternator. Replace it with a 110 amp alternator or the ECU will get emotional and trigger the charge system warning lamp. Don't buy an alternator from freakin Advance Auto .






.
Ain't that truth. I had no choice on my replacement alternator to get back to work in the morning. The Advance Auto alternator lasted 1 week and failed on my way down the interstate at night. The local Advance staff at least offered to return it for me and I bought a Motorcraft from Rock Auto.

I've pretty much given up the local parts stores, they mostly carry poor quality.
 
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Wanderfloof

Wanderfloof

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Ok, when you replace the alternator, use one from a NAPA dealer or a Motorcraft unit from Rock Auto. Unless your Expy came with factory navigation you have a 110 amp alternator. Replace it with a 110 amp alternator or the ECU will get emotional and trigger the charge system warning lamp. Don't buy an alternator from freakin Advance Auto .






.
Does it matter if I have the upgraded sound system?
 
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Wanderfloof

Wanderfloof

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Update here to kind of close it out.

Alternator was replaced and the issues are gone with the charging light and battery meter pegging high.

I kept getting a weird reading of .1-.3v (would spike up to .3v for the briefest moment and then drop to .1v) on the chassis ground, but no source found. I did clean up the connection and made sure it was nice and tight, still had the spike.

I do think my radio has the wonderful parasitic draw but not at a rate enough to concern me yet since it's not sucking my battery dry and I'm about to change out the head unit.
 
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