73 Super Beetle Voltage Regulator

jashv · Post by **jashv** » Thu Feb 27, 2003 12:18 pm

I have a 73 Super (built July 1973) and I cannot figuire out the wiring for the Voltage regulator. My 72 has more wires hooked up (4) but the 73 only has 2 that are available. One is a light brown with a round ring, one is a red and black lead that comes from the main wire harness down the drivers side, and that is all, what am I missing? There are some smaller wires, but I believe they go to the seat belts. The rear of the car is not getting juice, even the lights in the back to do not work.

Post by **Marc** » Thu Feb 27, 2003 12:31 pm

I'm not enough of a mindreader to make heads or tails out of the question. Here's the schematic for your car, see if it gets you off to a good start. http://vintagebus.com/wiring/1303_USA_f ... 1972-1.jpg http://vintagebus.com/wiring/1303_USA_f ... 1972-2.jpg http://vintagebus.com/wiring/1303_USA_f ... 1972-3.jpg
If you have an alternator rather than a generator, and it has a solid-state external regulator under the back seat, you'll need this one: http://vintagebus.com/wiring/1303_USA_f ... 1973-1.jpg
If you have an alternator that has the regulator built in (just a B+ post, a D+ terminal, and a ground screw on the alternator) there is no good schematic published for it but electrically it's identical to the external-regulator version, it's just inside the alternator instead of in the cab so you'll see fewer wires.

jashv · Post by **jashv** » Thu Feb 27, 2003 12:49 pm

What is the best way to tell if this is a alternator or generator ?? I thought the later half of 73 they went to alternator. There is a small plastic box in the back behind the back seat, I THINK it says motorola and I believe there was a regulator there to, but it is missing, that is where the phantom wires come from.

Speedy Jim · Post by **Speedy Jim** » Thu Feb 27, 2003 1:46 pm

The MOT box is the regulator.
You have an alternator (MOT) with external
regulator.

The Red/Blk wire just goes to the starter
solenoid. The battery wires are Red/Wh
and are jumpered together in plastic splices.

Brw is ground. There should be a thin solid
Blue wire in the harness. This goes to the
regulator (D+) for the GEN warning light.

There is info on my web site about the
Alt wiring.

Small wires on the battery side under the
seat are for the Diagnostic Plug. See the
article: "What is this plug in my engine bay?" on my web site.

E-mail if you need more.

Speedy Jim
http://www.nls.net/mp/volks/

Post by **Marc** » Thu Feb 27, 2003 2:02 pm

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by jashv:
What is the best way to tell if this is a alternator or generator ?? I thought the later half of 73 they went to alternator. <HR></BLOCKQUOTE>

Alternators are larger in diameter at the pulley end than they are at the fanhousing end; generators are cylindrical. Generators have a large D+ terminal and a small DF terminal. Alternators have a large B+ post and a small D+ terminal, and if they're the early ones with the external regulator they'll also have DF and D- terminals.
The first alternators I saw were on `73 Convertibles, then on `73 SuperBeetle Sedans. Don't know that I ever saw a `73 Standard with a factory-installed alternator but that doesn't mean they don't exist, maybe none got shipped to the Northwest. I would expect that your car was alternator-equipped from the factory.
The early alternators were all external-regulator style but by `74 the internal-regulator ones started to show up and were generally used as replacements for the other kind, leaving the DF and D+ wires in the harness unused.
If you have power to the front of the car but the rear lights don't work, I can absolutely guarantee you that the alternator and regulator wiring have nothing to do with the problem.

jashv · Post by **jashv** » Thu Feb 27, 2003 2:28 pm

Thanks Speedy Jim, I think I am getting it, I have some pics here http://www.72superbeetle.com/help.htm sorry for the ugly page and large pics, if you click they will get larger. I found my brother-in-law hooked one up to the battery, the one in picture one, bottom left corner. (black tube with 2 brown/wht wires) Not sure if that went there so I removed. Now I have two brown/wht from that tube 2 red blacks and that small siver box with the one lead coming from it. Can you review and maybe explain again? THANK YOU GUYS SO MUCH FOR YOUR HELP !

Post by **Marc** » Thu Feb 27, 2003 2:56 pm

OK, there's definitely an external voltage regulator for an alternator bolted to the body under the back seat. I don't know the alternator part numbers off the top of my head and the picture doesn't show the only area of interest (the top of the alternator on the other side of that hose where there will either be a single terminal or a big round rubber plug with 3 terminals in it) so I can't say for sure that the regulator is still in use.
The silver box you're holding in-hand is the rear window defogger relay, J9 in this diagram: http://vintagebus.com/wiring/1302_from_ ... _items.jpg (this shows it receiving power from a generator's voltage regulator, on your car it should be coming from one of the large red wires in the white junction block under the back seat).
The OEM battery had a center tap, where a small yellow wire with red stripe connected for the VW dealer diagnostic computer. There are also a brown wire and a brown/white wire that go to the diagnostic socket- they went to the battery end and body end of the battery ground strap, respectively. If you're having trouble following those late-model diagrams (most people do) you might want to look at a `72 diagram that's still laid out in a semi-pictorial manner, just to get your bearings and make it easier to determine a wire's function by its color - of course you need to check against the `73 diagram when connecting wires, since there are some differences especially at the fusepanel. http://vintagebus.com/wiring/1300_and_1 ... 1971-1.jpg http://vintagebus.com/wiring/1300_and_1 ... 1971-2.jpg

Again, no loose wires under the back seat will prevent the rear lights from working if power is making it to the front of the car.

[This message has been edited by Marc (edited 02-27-2003).]

jashv · Post by **jashv** » Thu Feb 27, 2003 3:10 pm

So C1 is the regulator, right? Is S1 the black fuse assembly? What is E17?

The plug to the alternator has the connectors like this |_| and to the right of that is a small screw with two wires coming from that.

jashv · Post by **jashv** » Thu Feb 27, 2003 6:26 pm

I was wrong, the rear lights do get power, no problems there like I thought before.
Following http://vintagebus.com/wiring/bug-73-super-a.jpg the wires from the alt are red/white and black I have those, they come in to the car and go into that clear/yellowish plug in my picture. Since the diagram has just one white and one black going into the rear window relay and mine has more I took out the others. Now I have a blue wire which did fit my 72 regulator on one side. That leaves a green, red and 2 red/whites to find. Per the diagram there should be a red/white from the battery to the regulator, the only leads from the battery go to the starter and one that comes from the bat thru one of those black tubes and into the wires in the bundle (ones that come down the drives side of the car)
Found the yellow wire with the red strip, at this time it is not hooked up. Got the brown and the brown/white wires hooked up.
At this point I think I have to quit and pay the $$ to have a shop look at it.