I had a "bad bearing" sound, but couldn't locate it using the Hose Trick (too $&# noisy under the hood), so I pulled the alternator out; It turned a little stiff, so I took it in for a rebuild. It had always charged at 14.5V on the dash gauge, I was just worried about it blowing out if it had a bad bearing....

$114 later for a brush kit and bearing swap, I reinstall the unit - guess what, it charges at BARELY over 12V! I took it back today, the Tech said it had a "phase out"...and fixed it. I brought it home, re-installed it, and - barely over 12V! Did these guys trash my alternator, or is it something else?!? The voltage regulator is part of the ECM, I believe - could this have somehow gone south, between the removal and re-installation? Doesn't make sense to me....

The truck is DOWN HARD until I get this solved! Help!

 

There is a fuse in the underhood fuse box.
Could this have somehow been blown?
Did the shop test the Alt for output before handing it back to you?

 

- thx for the quick response!

...the Tech said that it had about 10a before he fixed it, and was getting an easy 90 without winding it up after the fix; Which fuse, and where? What does it do?

 

AHA! The Fusible Link / 140A fuse in the PDC was SMOKED - of COURSE, NAPA and Schucks and Autozone don't carry it.....

 

You can use the one that "almost fits", just bent the tabs to make it fit. Take yours in to the auto parts store and match it up, you will see what I mean.

I picked mine up at Murray's discount auto (michigan and ohio). The one I am talking about is made by Littlefuse, and the tabs are to long. Just bend them like the oem. I think it cost 3 bucks. Kevin

 

....thought I should stick with the "OEM", just in case the alternator wasn't up-to-snuff, I wouldn't want to compound or mask any issues with a barnyard fix!

Note: The guy at Napa tried to convince me that a 120 amp fuse would work...even after I reminded him that I had a 136 amp alternator...?

 

Well, it will work. Just not for long.

 

Yea it would last until the first cold start that requires some serious winding on the starter...

 

HAH! Exactly! Get it rev'ed up, turn on some lights / stereo / heater fan, put a draw on the alternator, and POP!

The rebuild seems to have worked, no more whining from under the hood, but.....it seems that it takes notably longer to get up to the 14.5V reading on the gauge. Are my batteries getting weak?