Try this again. I have a 1974 beetle with a alternator/with external regulator. I am replacing the engine that has a generator installed. How do I use the existing wiring for the generator?


Asked by May 05, 2013 at 10:34 AM about the 1974 Volkswagen Beetle

Question type: Maintenance & Repair

The 1974 alternator has a 3 prong clip that has a DF, D+, and D- terminal which is connected to the external voltage regulator. The B+ is run to the battery. There is another wire on the B+ side, where it goes I am not sure.The generator appears to be wired similarly. I have another parts bug that used a generator that I can remove the voltage regulator from. Any way to wire this up?

10 Answers

under the backseat, there is a voltage regulator. why aren't we using this one?...oh yeah, are you are trying to use a one-wire replacement? The B+ and ground connection are the only ones we should be concerned with, the other wires should be ignored, if NOT using an external regulator- will have to make a/look at a drawing of the old system to make a schematic so we both can understand what to do with these extra wires-

3 out of 3 people think this is helpful.

DF= field coils D+ generator plus voltage D- =ground---a one wire lays waste to these---snip ' it.

3 out of 3 people think this is helpful.

yes...the blue wire, okay connect your new alternator one wire output to the secondary of the voltage regulator, this should make the blue light come on under under-voltage conditions~....whew, got that one figured kinda bugged me too...this simplicity is not without complications such as indication for non-functioning conditions...


This is the set up. So I use the B+(red/white) wire from the alternator connect to the D+ post on the generator. Then I use the DF(green) wire from the alternator to the DF post on the generator. The D-(brown) wire on the alternator becomes the ground on the generator. It will be best to replace the external Motorola regulator with the one for a generator.

wow...okay have not dealt with those...good work!~

1 out of 1 people think this is helpful.

Seems like it would work. Just changing wire locations and the voltage regulator to one that is common to the generator. I think the wiring form the regulator out should stay the same. I'll let you how it turns out. Any other opinions?

1 out of 1 people think this is helpful.

well DF=field coils (we definately don't need that) D+ sane as B+ You've got a "lineman's splice" into the B+, not quite sure how this will know that it has reduced fewer than 12.5 volts....think the ole voltage regulator had a reduced voltage blue light enabler...would make sense~ the field coils are not used with solid state, this voltage causes the pulses from the olde tyme coils, much like the old fashioned voltage regulators that GM would use a bank of three, ford two...back in the day...


I used a 71 Ford voltage regulator with my VW alternator. Way more dependable. Try this diagram.

11 out of 11 people think this is helpful.

I used a 71 Ford voltage regulator with my VW alternator. Way more dependable. Try this diagram.

2 out of 2 people think this is helpful.
Derek Wheelock

This answer is late for this post, but.....why not just install the alternator and stand onto the replacement motor? It is a much more reliable system than the generator.

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