Alternator or regulator problem. (Aircooled 74 Beetle Type 1)?

Question

My bug didn't start yesterday,but it made a sound of grinding teeth gears and relays, I believed the starter didn't have enough power, then at some point didn't make a sound at all. I thought battery was dead, and now I think it just needs to be recharged because today I tried another battery, it started fine but after several minutes I decide to turn off the engine and start again but I got the same issue, now I think both batteries are out of power but fine. The curious thing is while engine running, you can unplug the battery and the engine keeps working, it looks like the alternator didn't have enough power to charge the battery back, some of you may think is the alternator, by the way I already check the tighness of the belt. Is there any chance the problem is the regulator? if so, how can I diagnose this?. Or maybe the cable that goes back to the battery?. And if you know how; how can I detect a bad ground?. Thanks

Answer 1

If you had the car running with the battery disconnected you more than likely destroyed the regulator inside the alternator. It probably was not working to begin with from the sounds of it. It is NOT your starter. First you would need to replace your alternator and never run the car with the battery disconnected. Before you even hook up the battery make sure it has a FULL charge and that it is a good battery this will also destroy a regulator.

The only thing to do with your starter that I would recomend is cleaning all of the electrical contacts and make sure that all of your wiring is secure and making good contact as well as your ground strap or wire.

If after you do these things and something is still draining your battery you need to do some electrical testing. I don't know if you know how to use a multimeter but now is a good time to learn.

First thing to check would be parasitic draw from battery. You check this by disconnecting the Neg cable from battery and measuring with multimeter the amount of amps from battery post to neg cable. If it is over .03-.04 with the key OFF, something is draining your battery that should not be.

I would also check for continuity from alternator to battery.
Take an amperage reading from alternator to battery (should be at least 51 amps @ 1100 RPMS.

I don't know if this is a super beetle or not but they are the same mechanically. The most helpful Technical information and group of people you will ever find is:


www.superbeetlesonly.com

If you go there I can help you further if needed.

JSPEED (screenname)

Answer 2

It's your starter. The noise you hear is the teeth on it grinding. The car runs off the alternator when running, it also charges the battery back up so if te battery was low the car would turn over very slowly not make a grinding sound. Get a Bosch stater SR15N easy to put it and it will fix your problem.

Answer 3

Been there...after changing the voltage regulator twice I ended up taking it into a VW specialist. (I usually did my own maintenance)

It ended up being the generator brushes - the little graphite looking wedges you can see in the generator. I had them professionally replaced but later educated myself on how to do it on my own. The "How to keep your VW alive - repair for the compleate idiot" book is what I used.

Answer 4

My vote is the alternator. you should go to a mechanic to verify...