Alternator Charging Issue (New Owner)

[NickGaige]

Okay a little background. My dad bought this 65 bug and converted it into a dune buggy. Besides that, it has pretty much sat for the past 22 years. We got it running and maintenance up to date and such but we can't keep it charged.

It does have an alternator rather than a generator. However, when started the dash light doesn't come on unless you rev it fairly high and then it will light up and stay lit. What could that mean?

We are both newbies when it comes to volkswagen so any help would be appreciated!

[NickGaige]

Also, the battery is a good battery and we have tested the voltage on the alternator and it's has the correct voltage. So obviously it's a wiring issue that needs to be traced down.

Now my question is - does the dash light lighting up mean its charging? any idea why it only lights up with a heavy rev?

[Q-Dog]

If it is an alternator, it works pretty much like any other alternator on any other car. There is nothing VW specific about electricity.

Alternator light should come on with the key and go out once the engine starts. Light on when running means it isn't charging. Use a multi meter to test alternator output and to measure battery voltage while the engine is running. Could be a dead alternator, could just be a loose wire.

It would help to know which alternator you have. Does it have internal or external regulator?
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Brian

'69 Dune Buggy
'69 Beetle Convertible
'70 Beetle

[andk5591]

Once the revs are back down, does the light stay off? My understanding is that the alternator requires and initial voltage supplied by the light circuit to start charging and should continue to charge once that happens, but in my experience that is not always the case.

Anyway - a little more detail is needed. Which alternator - does it have an external regulator or is it internally regulated?

Here is something funny that I run into with my 65 (Bosch AL82 internally regulated) at the beginning of the season. The alternator light will come on some even after driving a few miles. It will go out eventually and after I have driven the car more (after a couple days), the problem goes away. Never been a problem long enough to actually troubleshoot other than double checking my connections. Mentioned it to another mechanic once and he said he has seen this on occasion with cars that sit for a while and that it routinely clears up itself. Has happened the last 2 years.

Another obvious thing for you to look at is the fan belt. Is it loose ans slipping?
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D-Dubya Manx clone - 63 Short pan,1914.
Rosie 65 bug - My mostly stock daily driver.
Woodie 69 VW woodie (Hot VWs 7/12).
"John's car" 64 VW woodie - The first ever
Maxine 61 Cal-look bug - Cindy's daily driver.
Max - 73 standard Beetle hearse project - For sale
66 bug project - Real patina & Suby conversion
There's more, but not keeping them...