Charging woes

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Amskeptic
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Re: Charging woes

Post by Amskeptic » Mon Sep 11, 2017 10:44 pm

appetite wrote:
Sat Sep 09, 2017 11:57 am

started the bus up and hooray, the VDO is showing 13+ volts.
I could not have diagnosed the problem without your ideas.
James
Man, good for you, James. That is a fiddlef**ky repair job.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

appetite
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Re: Charging woes

Post by appetite » Sun Sep 24, 2017 2:54 pm

Well, my celebration might have been premature. The alternator is up to its old tricks after a week or so of good behavior. It was really a joy to have a full charge pulsing through the system. The lights were brighter than I recall them being in a long time.

Maybe there's more gunk down there than i thought, or maybe the rings are rutted and are holding onto contaminates. I'm going to give the rings another cleaning before taking more drastic measures (replacing the alternator).

Question: can i use something more abrasive to clean the rings than a pencil eraser? How about some sandpaper?

Thanks,

James

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Amskeptic
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Re: Charging woes

Post by Amskeptic » Sun Sep 24, 2017 5:16 pm

appetite wrote:
Sun Sep 24, 2017 2:54 pm
Well, my celebration might have been premature. The alternator is up to its old tricks after a week or so of good behavior. It was really a joy to have a full charge pulsing through the system. The lights were brighter than I recall them being in a long time.

Maybe there's more gunk down there than i thought, or maybe the rings are rutted and are holding onto contaminates. I'm going to give the rings another cleaning before taking more drastic measures (replacing the alternator).

Question: can i use something more abrasive to clean the rings than a pencil eraser? How about some sandpaper?

Thanks,

James
I used 800 wet or dry sandpaper on a tongue depressor stick stuck in the generator of an idling engine. Worked very very well very very quickly. That's a warning.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

appetite
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Re: Charging woes

Post by appetite » Sun Sep 24, 2017 6:07 pm

Ha! I'm not that brave. Oof!

But I'll get some sandpaper and see if I can clean those rings better this time around.

appetite
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Re: Charging woes

Post by appetite » Wed Apr 04, 2018 1:36 pm

Reviving this thread, since I put the bus away for the winter without a resolution and Spring will soon be sprung (although winter is never ending here in NJ, apparently...)

The battery was dead when I tried to start the bus over the weekend. I wonder if, over the winter, there was a slow drain on the battery somewhere?

Jumped it, got it started, and it was charging at juuuuust 12 volts. So the alternator is behaving as described last Autumn. Bummer.

I'm going to try the sandpaper method, but I also wonder if I could use a product like Gumout on a paper towel to wipe away any residue on the slip rings.

Is that a possibility or will Gumout damage the alternator?

Thanks.

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Amskeptic
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Re: Charging woes

Post by Amskeptic » Sun Apr 08, 2018 7:59 pm

appetite wrote:
Wed Apr 04, 2018 1:36 pm
Reviving this thread, since I put the bus away for the winter without a resolution and Spring will soon be sprung (although winter is never ending here in NJ, apparently...)

The battery was dead when I tried to start the bus over the weekend. I wonder if, over the winter, there was a slow drain on the battery somewhere?

Jumped it, got it started, and it was charging at juuuuust 12 volts. So the alternator is behaving as described last Autumn. Bummer.

I'm going to try the sandpaper method, but I also wonder if I could use a product like Gumout on a paper towel to wipe away any residue on the slip rings.

Is that a possibility or will Gumout damage the alternator?

Thanks.
Did you disconnect the negative battery cable over the winter? That is a mandatory step.
If not, a dead battery is actually an expected result. I think even good alternator diodes leak a little over extended periods of sitting. You should know, too, that low batteries can freeze in very cold temps. I would store mine in the basement on a top wood shelf near a casement window, and trickle charge it once mid-winter.

GumOut on a paper towel is fine as long as you do not spray directly into a rotating alternator. It will flash ignite. There are electrical cleaners that allow you to spray into a running generator/alternator.

Try abusing the hospitality of your local automotive electrical shop (not AutoZone) and ask for an in-car alternator test.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

appetite
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Re: Charging woes

Post by appetite » Mon Apr 09, 2018 4:52 am

I did not remove the negative cable over the winter. Will do next year.

I'll try both the sandpaper and Gumout and report back.

Thanks.

appetite
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Re: Charging woes

Post by appetite » Sun Apr 22, 2018 3:13 pm

Finally a nice weekend, so I dug into this task, with poor results. I tried the eraser, the sandpaper and the Gumout. But alas, the alternator is behaving erratically and poorly, charging below 12v. Is there anything others with similar symptoms have tried?

I'm trying to resign myself to replacing the alternator, although from the research I've done, it seems like a bear of a job. Has anyone tried successfully with the engine in?

Grrr!

Thanks,

James

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Amskeptic
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Re: Charging woes

Post by Amskeptic » Mon Apr 23, 2018 7:49 am

appetite wrote:
Sun Apr 22, 2018 3:13 pm
I'm trying to resign myself to replacing the alternator, although from the research I've done, it seems like a bear of a job. Has anyone tried successfully with the engine in?
Grrr!
James
Remove battery cable, fan belt, thermostat, carburetor, and coil/spark plug wires from fan housing. Take a break.
Remove alternator hold down strap, wires, both 10mm bolts from fan housing-to-upper tins, dog house tin, then doghouse outlet tin. Take a break.
Obtain two wood blocks 2x4x3or4. Lift fan housing upwards and stick the wood blocks underneath between the upper tins and the lower edge of the fan housing. Jblair 630 and I used these huge things to lift under the fresh air hose outlets against the intake manifold:

Image


Last summer, I used a hammer handle on the left and a fresh air collar on the right to keep the fan housing up:

Image


You will see four 10mm bolts holding the fan plate to the fan housing. Remove them, and you can pull the whole assembly out from the engine compartment. Note the gap between the fan and the fan plate, you shim the fan with spacers that look a lot like the fan adjustment shims to get a 1-2mm gap.

Loosening the fan requires that you get a good wrench on the inner pulley flats and a big socket (30mm) on the fan nut. Once you have done it a few thousand times, it is easy enough.
Colin

Image
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

appetite
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Re: Charging woes

Post by appetite » Tue Apr 24, 2018 11:00 am

Oofa.

If swapping the alternator is my fate, I shall succumb. But first, a few more tests.

I trickle charged the battery overnight. Bought a multimeter. Got a reading of 12.6 at the battery with the engine off.

With the engine running, battery reads 12.14. And with + post on the B+ terminal on the alternator and - post on the neg battery terminal, I'm getting the same 12.14.

So I assume the alternator is putting out some charge, just not enough to reach the preferred range of 13.5 to 14, yes?

Maybe there's still hope that something is amiss with the brushes or the rings or some connection. I'll take it apart again...

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Amskeptic
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Re: Charging woes

Post by Amskeptic » Tue Apr 24, 2018 8:44 pm

appetite wrote:
Tue Apr 24, 2018 11:00 am
Oofa.

If swapping the alternator is my fate, I shall succumb. But first, a few more tests.

I trickle charged the battery overnight. Bought a multimeter. Got a reading of 12.6 at the battery with the engine off.

With the engine running, battery reads 12.14. And with + post on the B+ terminal on the alternator and - post on the neg battery terminal, I'm getting the same 12.14.

So I assume the alternator is putting out some charge, just not enough to reach the preferred range of 13.5 to 14, yes?

Maybe there's still hope that something is amiss with the brushes or the rings or some connection. I'll take it apart again...
Refresh me, the alternator warning light does work, yes? On with ignition, out with revving the engine?
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

appetite
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Re: Charging woes

Post by appetite » Wed Apr 25, 2018 9:38 am

Yes, GEN light on at ignition, out with rev. Pops back on at low idle, off with rev.

Could the low volts result from a loose fan belt?

Does the battery have to be fully charged for the alternator to produce suffiencent voltage?

Are there any other factors I can eliminate before I bite the bullet and dismantle my otherwise wonderfully running bus at the precipise of the driving season?

Thanks very much,

James

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dingo
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Re: Charging woes

Post by dingo » Wed Apr 25, 2018 10:56 am

Pops back on at low idle, off with rev.

Diode(s) have gone south
'71 Kombi, 1600 dp

';78 Tranzporter 2L

" Fill what's empty, empty what's full, and scratch where it itches."

appetite
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Re: Charging woes

Post by appetite » Wed Apr 25, 2018 6:55 pm

Is there a way to test? And can the diodes be replaced?

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dingo
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Re: Charging woes

Post by dingo » Thu Apr 26, 2018 11:51 am

set multimeter to AC volts, and with engine running, put meter leads across battery...should be less than 50mV...if more than that then one or more diodes are bad

replacement is possible, but requires a fair amount of dissassembly
'71 Kombi, 1600 dp

';78 Tranzporter 2L

" Fill what's empty, empty what's full, and scratch where it itches."

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