More alternator troubles

Bus, Microbus, Transporter, Station Wagon, Vanagon, Camper, Pick-Up.

Moderators: Sluggo, Amskeptic

appetite
Getting Hooked!
Status: Offline

More alternator troubles

Post by appetite » Wed Jul 17, 2019 4:30 pm

Kind forum,

I'm in a bind. The alternator I replaced last year, less than 2000 miles ago, is not charging. This morning, after getting gas, the GEN idiot light was not coming on at the turn of the key, so I changed the bulb. This did not change the output of the alternator. Now, sometimes the GEN idiot light is on before start-up, sometimes not. Either way, it does not change the output of the alternator.

The only thing I did to the electrical system was to add a cigarette lighter/power outlet to charge a phone. Did I do something stupid and fry the alternator? It was working just fine and then kaput. I'm kicking myself! Of course, our epic summer roadtrip is just 2 1/2 weeks away. If I don't get this squared, the trip is off, obviously.

What I've done so far:

1. Replaced the Gen idiot light bulb (what a PIA)
2. Cleaned battery ground cable
3. Cleaned transmission ground cable
4. Inspected brushes (look pretty OK)
5. Tested voltage at Alternator: 12.4 (volt meter, positive at B+, ground at body of alt)
6. Tested voltage at battery: 12.4

Where should I go next?

For reference: 69 bus with a 1600 dual port, alternator conversion (Bosch AL82N).

Despondently,

James

User avatar
tommu
Old School!
Location: Sunny Burbank
Status: Offline

Re: More alternator troubles

Post by tommu » Wed Jul 17, 2019 10:18 pm

I am not much help troubleshooting this - but curious why you needed to replace the previous alternator? Did it have the same symptoms and were you able to get it tested?

User avatar
asiab3
IAC Addict!
Location: San Diego, CA
Contact:
Status: Offline

Re: More alternator troubles

Post by asiab3 » Wed Jul 17, 2019 11:37 pm

Hi James,

With the key on, can you get the charge light to flicker by wiggling the bulb housing? Most instrument cluster light issues I are are bulb sockets that aren’t fully seated, especially if the socket or nearby wires are recently handled.

Whenever the bulb refuses to light with “key on, engine off,” you can elimitante half the possible causes by immediately going back to the engine compartment and grounding the alternator Df (blue) wire. This should light up the idiot light if everything under the dash is perfect. This would indict the alternator. If the light does not light up, the problem is forward of that connector you just touched. You may need a helper.

Robbie
1969 bus, "Buddy."
145k miles with me.
322k miles on Earth.

appetite
Getting Hooked!
Status: Offline

Re: More alternator troubles

Post by appetite » Thu Jul 18, 2019 5:20 am

Thanks Robbie. I'll try this morning.

appetite
Getting Hooked!
Status: Offline

Re: More alternator troubles

Post by appetite » Thu Jul 18, 2019 7:13 am

OK, I grounded the blue wire and the GEN idiot light came on.

So the issue is with the alternator, I presume. Is there anything else I should diagnose before I bite the bullet and get a new one?

And what in God's name could have fried the alternator? As I mentioned, I swapped in a new one less than 2000 miles ago. Are parts really this crappy or did I do something stupid? And, what can I avoid to prevent failure in the future?

Thanks,

James

appetite
Getting Hooked!
Status: Offline

Re: More alternator troubles

Post by appetite » Thu Jul 18, 2019 2:39 pm

I ordered a new alternator. But man, I'm really perplexed about why this other one is not charging. It seems ludicrous that it lasted only 2000 miles, right? Am I crazy?

Something fried this thing or it was an unmitigated piece of shit out of the box.

Sorry to repeat myself, but are parts really this crappy or did I do something stupid? And, what can I avoid to prevent failure in the future?

appetite
Getting Hooked!
Status: Offline

Re: More alternator troubles

Post by appetite » Sat Jul 20, 2019 11:05 am

Folks at thesamba think it might be a failed regulator, but I'm still flabbergasted:

https://www.thesamba.com/vw/forum/viewt ... p?t=722360

Any thoughts?

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: More alternator troubles

Post by Amskeptic » Sun Jul 21, 2019 8:02 pm

appetite wrote:
Sat Jul 20, 2019 11:05 am
Folks at thesamba think it might be a failed regulator, but I'm still flabbergasted:

https://www.thesamba.com/vw/forum/viewt ... p?t=722360

Any thoughts?
Return to a 38A generator. Seriously. Old school technology that is robust. But for the trip, throw in another alternator with a real warranty.
ColinNoTimeForCrap
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
Getting Hooked!
Status: Offline

Re: More alternator troubles

Post by appetite » Wed Jul 24, 2019 1:27 pm

Thanks everyone for your help and expertise.

I swapped in a new Bosch alternator today, and the bus is charging at 14.4 volts at idle. I can only assume the previous 'new" Bosch was a dud. :angryfire:

Here's hoping this one lasts more than 2000 miles.

Thanks again,

James

appetite
Getting Hooked!
Status: Offline

Re: More alternator troubles

Post by appetite » Thu Jul 25, 2019 9:02 am

Hey quick follow-up:

Does the alternator naturally get hot after running for, say, 1/2 hour? Hot to the touch hot..?

Normal?

Thanks,

James

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: More alternator troubles

Post by Amskeptic » Thu Jul 25, 2019 11:14 pm

appetite wrote:
Thu Jul 25, 2019 9:02 am
Hey quick follow-up:

Does the alternator naturally get hot after running for, say, 1/2 hour? Hot to the touch hot..?

Normal?

Thanks,

James
No, it should not be unduly hot. Might be a clue. What is your resting battery voltage?
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
Getting Hooked!
Status: Offline

Re: More alternator troubles

Post by appetite » Fri Jul 26, 2019 8:14 am

Resting battery voltage is 12.8

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: More alternator troubles

Post by Amskeptic » Sat Jul 27, 2019 11:11 am

appetite wrote:
Fri Jul 26, 2019 8:14 am
Resting battery voltage is 12.8
We need to carefully track this symptom down. Question all assumptions. These failures may be related to each other. Even if you answered that the cooling duct was correctly installed, check again. Is it actually installed correctly?

etc
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
Getting Hooked!
Status: Offline

Re: More alternator troubles

Post by appetite » Sun Jul 28, 2019 11:02 am

Hi Colin,

Yes the cooling duct was installed correctly, with the vent on the bottom. It is wired correctly. The pulley is aligned and the fan spins freely.

Is there anything else I should check?

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: More alternator troubles

Post by Amskeptic » Thu Aug 01, 2019 12:49 am

appetite wrote:
Sun Jul 28, 2019 11:02 am
Hi Colin,

Yes the cooling duct was installed correctly, with the vent on the bottom. It is wired correctly. The pulley is aligned and the fan spins freely.

Is there anything else I should check?
Sorry I'm late! It has been hot out here too.
Did your prior alternators ever run hot?
We need to track this down.
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

Post Reply