I may order that terminal block like 94 suggested. Just to have on hand. Not sure how much I trust that stud on the alternator.. They're cheap enough. Amazon has them too. Probably Ebay as well.

 

Let's hope it stays fixed this time.

 

Drove the truck a few times since I cleaned up that field service connection on the alternator. So far so good. Just don't know how much I trust that terminal stud on the terminal block. Kinda rinky dink with those cheesed up threads. I just ordered a repair kit for that alternator (inspired by 94's suggestion). The kit is only $20 delivered. Comes with the terminal block and a new brush. The alternator has only 20,000 miles on it so the brush is probably more than fine. But I may put the new brush on anyway since I'm there. We'll see. Oh, and my battery is retaining a full charge. 12.6 volts versus 12.35 volts previously. I look back and that 12.35 volts should have tipped me off that the alternator wasn't fully charging the battery and to check that field service connection. I never claimed to be the sharpest bulb in the drawer.

 

Well HY, the voltage fluctuation returned about a week ago. It would happen on start up but by the time I got out of the driveway it would cease and stay that way. That pattern has held ever since. But my OCD was triggered so I yanked the alternator back out again, tore the back off, and replaced the terminal block and brush with the new ones I bought. Fired up the truck and the needle immediately went to its home position and stayed that way throughout my 8 mile test drive. Hoping it stays that way now. Amazing how a few boogered up threads can lead to so much aggravation.

 

And 94, I think replacing that terminal block was the right path. Yes the threads were bad but I think there was more wrong with that terminal block than just the threads. Thinking the connection between the stud and the metal strip was suspect too. Probably got mangled somewhere along the way by overtightening or bending or something...who knows. Only real solution was to replace the dang thing.

 

Oh, and I removed all those ridiculous ground cables I had running all over the place. Went back to the one original ground cable going from the engine ground stud to the alternator and then ran one 10ga ground cable from the regulator mounting bolt to the engine ground stud. Cleaned up nice. Done!

 

We havin' fun yet?

 

It's like there are layers to this mystery. Peel back one layer, find another. Rinse and repeat. I really think the problem is inside that terminal block. I say that because I have checked that field wire connection numerous times over the past whatever days, months, and years. I grab the stem of the terminal and try to rotate it. Nope. Solid as can be. But when I wrench down on it or simply remove and reattach, it fixes itself...at least for a little while. Gotta think however that stud is attached to the metal strip in that block terminal it is somehow compromised or weak. You can't see it because it's buried in the plastic block.

Another thing I noticed. The old brush is worn unevenly. There are two brushes, an outer one and an inner one separated by 1/2" or something. Presumably one is power and one ground...one brush for each field wire (I dunno, I'm no electrician). But one of the brushes is noticeably shorter than the other, by a good .150 inches maybe more. Don't know if that's normal but I did notice they were the same length on the new brush assy. Do you know if they typically wear at different rates?

 

So far as I know, they *should* wear at the same rate..... they are both in the exact same environment, doing the same job..... I have no idea if current flow direction makes a difference on that though. I don't generally rebuild alternators, just replace 'em. But, electric motors I have rebuilt, the brushes all wear at pretty much the same rate.....

 

There's gotta be something going on with that alternator. The terminal block, the brushes, sumpin'. Here I've been blaming myself all along. I'm taking that back. Lesson: Avoid using remanufactured parts if you can.