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> G lite, Not going off.
Spoke
post Feb 6 2018, 09:33 PM
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QUOTE(JFG @ Feb 6 2018, 03:22 PM) *

Beware conducting this test. I took 45 - 60 seconds before fire started in the alternator wiring loom.


Excellent point. This "Full on" alternator test should not be done for a long period. The goal is to see the alternator give full voltage when the VR is shorted. Once a healthy voltage is observed, the test can be concluded.
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malcolm2
post Feb 14 2018, 08:01 AM
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QUOTE(rgalla9146 @ Feb 3 2018, 06:07 PM) *

Brushes


I am going with this suggestion.....KINDA. I have slowly been working on the car. ALT is out and now it has been taken apart. Brushes actually look good.

Attached Image

BUT they have not been aligned properly. Not really sure how the rebuilder would be able to check that either. You can see that one was hanging over the gap. So when that happens the part that is hanging over is not wearing away properly.

Not sure if it touching the 2nd contact point makes a difference, or if the unworn portion was long enough to touch the shaft makes a difference.

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malcolm2
post Feb 14 2018, 08:06 AM
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The video does not really show the bent-ness of the shaft. Maybe it is more visible close to the end of the 30 second video. Between the bent shaft and the mis-aligned brushes the ALT failed after 14 months, maybe 8000 miles..... THE END.

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worn
post Feb 14 2018, 09:40 AM
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QUOTE(malcolm2 @ Feb 3 2018, 12:38 PM) *

Took a 3 hour drive to Knoxville today. I watched the volt gauge. Seemed to be irratic. Hung at 11.4. But would jump to 13.5 for a short time them back to. 11.4. G lite was not on during the drive. After a short stop the re start is when the lite stayed on. Guage still at 11.4. I gotta get home.

Auto zone has a voltage reg. Is this a typical symptom of the easy to replace VR?


When buying a rebuilt alternator be sure that the lug doesn't short circuit to the case. Here is an excellent article that includes this. In some rebuilt alternator the positive lug is too long and when the cover is put on it touches.

See this:
http://www.914world.com/bbs2/index.php?sho...c=78981&hl=
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Mikey914
post Feb 14 2018, 06:47 PM
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Its all to common to have the builder use the longer terminal. Youll want to take in the metal back to have them see why it cant ne longer.

And ny the way i have new harnesses with all the clips and new rubber boot in stock at $88 if you fry one.
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Spoke
post Feb 14 2018, 07:06 PM
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QUOTE(malcolm2 @ Feb 14 2018, 09:06 AM) *

The video does not really show the bent-ness of the shaft. Maybe it is more visible close to the end of the 30 second video. Between the bent shaft and the mis-aligned brushes the ALT failed after 14 months, maybe 8000 miles..... THE END.


About the shaft wobble, to check it you would have to support both front and rear bearings then check for rotation variation. If just supported by the front bearing, you may just be seeing the play in the bearing as you rotate.

The misalignment for sure is an issue. It may have been that the one brush was slightly touching the other ring and causing the brush to touch both rings thus killing the armature current and causing the alternator to not produce voltage.

You could try to adjust the alignment of the brushes and have the alternator tested at Autozone or other FLAPS. Seeing how you've got 14 months on it the rest of the alternator it might still be ok.
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malcolm2
post Feb 14 2018, 07:34 PM
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at this point I think I am putting this one in a box and sticking it under the house. It has been rebuilt 3 times since 2013.

I have another one that was rebuilt at the same time this one was. And I found another rusty one in the garage today.

I have been spending time online trying to find a 79 bus ALT. AL108X is 70amps. They were only used on certain campers with a gas heater and a couple fans, so they are not easy to find. During that research, I read where Ratwell says an original ALT should go for 200k and a decent rebuild should make it 100k.

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malcolm2
post Feb 14 2018, 07:41 PM
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QUOTE(worn @ Feb 14 2018, 09:40 AM) *


When buying a rebuilt alternator be sure that the lug doesn't short circuit to the case. Here is an excellent article that includes this. In some rebuilt alternator the positive lug is too long and when the cover is put on it touches.



I was on The Samba today and the Bay Bus guys have some good threads on that subject. Lots of pictures of burnt up stuff. Make sure to use the little wedge pieces in the edge, and a gasket of some sort between the ALT and the back plate.
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malcolm2
post Feb 16 2018, 09:12 PM
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QUOTE(malcolm2 @ Feb 14 2018, 08:01 AM) *


Attached Image


Attached Image

Help me out here. 2 issues. How do I adjust the brushes to run in the center of each copper piece.

And 2: how do I retract the brushes while I insert the rotor?
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Spoke
post Feb 16 2018, 09:50 PM
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QUOTE(malcolm2 @ Feb 16 2018, 10:12 PM) *

Help me out here. 2 issues. How do I adjust the brushes to run in the center of each copper piece.

And 2: how do I retract the brushes while I insert the rotor?


Adjust the brushes by moving the entire plate the brushes are on. I see the ends of at least 2 screws, maybe 3. Remove the screws and see if you can insert a couple of small washers under the plate and replace the plate.

I added washers once on a motor on my furnace when the capacitor-start contacts were not closing when the motor would stop thus the motor wouldn't start. The washers moved the plate closer to the armature.

For retracting the brushes, use a small wire placed through the rear of the alternator to depress the brushes while you lower the armature into the case. Then pull the wire out when installed.
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malcolm2
post Feb 17 2018, 07:24 AM
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Washers! Of course. How would a rebuilder see or know the brushes were not aligned? None of that is visable when assembled.
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