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I, 1, 2, 1/2, 6
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Discussion Starter #1
OK, mind you, changing an alternator on a 6.0 is probably one of the easiest things to do under the hood. BUT, I believe it was january, my alternator went out. I went to Advance Auto Parts, got a new alternator, I'm back in business. here it is, AUgust, my batteries weren't getting recharged and it got progressively weaker and finally wouldn't start, just like in January. SO, I called up the Advance Auto I bought it from, explained to them what the deal was and I brought it in. I got a new one for free, the bearings in the one I put on in January were shot :doh: :tard:

SO, I get this new alternator, I go home and I put it on. I charged up my batteries for 60 minutes with a charger. It starts up. SO now, it still doesn't seem like it's charging them all the way. I let it run for about 15 minutes after I put it on. I toook an hour drive tonight. Last night I let it run for about 20 minutes after work. AND today when I went to start for the first time for the day, it cranked weakly but it started. SO now, I'm worried that the alternator may not entirely be the whole problem. What do you guys think?

heres a quick breakdown. new alternator in January, truck begins to crank weakly finally resulting in no start cause no juice, charged truck for 60 minutes with battery chargwer at work so I could get it started, alternator went out (bad bearings), new alternator installed Monday, truck still cranks weakly and i'm fearing that the alternator isn't the whole problem. What do you guys think?

maybe bad batteries now? Gonna go get them checked tomorrow.
 

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I used to go through an alternator per year ....It got old, had the same issue you did, they gave me a new one and it put out a zippy 9.4 volts. It was new off the shelf and didn't work. They gave me a NEW, not reman'd unit and it worked just fine.

They probably gave you another bad alt. Have them check it , then test the next one they give you before you put it on the truck.
 

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I, 1, 2, 1/2, 6
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Discussion Starter #4

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I, 1, 2, 1/2, 6
Joined
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2,261 Posts
Discussion Starter #5
I used to go through an alternator per year ....It got old, had the same issue you did, they gave me a new one and it put out a zippy 9.4 volts. It was new off the shelf and didn't work. They gave me a NEW, not reman'd unit and it worked just fine.

They probably gave you another bad alt. Have them check it , then test the next one they give you before you put it on the truck.
well damn! I guess i'll pull the multimeter out and test the alternator
 

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I, 1, 2, 1/2, 6
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Discussion Starter #6
ok I just put the multimeter on the batteries. Here's what I found.

WHEN I FIRST OPENED THE HOOD, truck had been sitting for about 4 hours from the last time it had been driven.

-Driver side battery - 12.6x volts
-Passenger side battery - 12.5x volts

I started the truck (starter still didn't seem to have it's same pep)

WHILE ENGINE RUNNING

-Alternator - 14.24 to 14.26 volts
-Driver side battery - 14.17 to 14.18 volts
-Passenger side battery - 14.19 to 14.21 volts

I went and turned the truck off, got out, came back to the engine compartment and checked the batteries again

-DRIVER SIDE BATTERY - I put the multimeter on it and it read 13.27 volts and was slowly dropping. I removed the leads and re applied them it was a few clicks lower and continued to drop, I removed them again and re applied them and watched it hit 13.00 volts and it stopped moving.

-PASSENGER SIDE BATTERY - I checked this battery next, it initially read 13.1x volts and was also dropping, I removed the leads and then checked again, same thing still dropping. I watched it drop down to about 12.96 volts. I removed the leads and tested one more time it was at 12.94 and slowly still dropping.

finally, after checking the passenger battery I checked the driver battery again and it was still at 13.00.

I now have questions and conclusions.

Is it normal for the voltage to drop like that? It was at 14.xx while the truck was running but when the truck wasn't running the batteries were in the high 12's for voltage.

I now know my new alternator is good. at 14.2x volts it's where it's supposed to be.

I'm gonna run by the parts store tomorrow and have them check the CCA's on the batteries :thumb:
 

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I, 1, 2, 1/2, 6
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Discussion Starter #7
well, it wound up being the batteries.

Went and got them tested

here's the results

-Passenger side battery

Voltage: 12.70V
Measured: 9 CCA :hehe: :doh:
Rated: 750 CCA
Temp.: 114*F

-FAIL-

-Driver Side Battery

Voltage: 12.89V
Measured: 520 CCA
Rated: 750 CCA
Temp.: 120*F

-FAIL-
 

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well, it wound up being the batteries.

Went and got them tested

here's the results

-Passenger side battery

Voltage: 12.70V
Measured: 9 CCA :hehe: :doh:
Rated: 750 CCA
Temp.: 114*F

-FAIL-

-Driver Side Battery

Voltage: 12.89V
Measured: 520 CCA
Rated: 750 CCA
Temp.: 120*F

-FAIL-
Yeah that'll do it. :crazy:
 

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I, 1, 2, 1/2, 6
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Discussion Starter #9
yup, she's fixed now!!!
 
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