Itinerant Air-Cooled

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

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?

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

Thanks Robbie. I'll try this morning.

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

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?

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?

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

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.

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

Thanks again,

James

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

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

Resting battery voltage is 12.8

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

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?

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