911 Alt wiring help !

[Sandeep]

Hi all,

I need some help wiring up this 911 alt that I have. The model # is :



The rear of the alt looks like this :



From what I can tell:

1. The two terminals on the top are labeled B+
2. The terminal in the middle, left is labeled D+
3. The upper spade plug is labeled DF
4. The lower spade plug is labeled (I think) D-

Questions:

I'm hooking this up to a 74 beetle with external regulator so I'm stumped as to where I connect the B+ wires on the alt. Does this alt have a built in regulator ?

If so, do I bypass the stock external regulator, and if so, where do I hook up the charging light for the dash ?

Or is this a generator instead of an alternator ?

All I have left to do is install this alt and the BAS exhaust and I can get my car on the road !! so I am really excited !!

Thanks for any help anyone can provide.

Sandeep

[Wally]

You need an external regulator by the looks of it. I have only wired up Mototola's, but it looks very much the same
Be sure to get the matching regulator! There really are a lot of differences in voltages and currents. Only a specialist that has a book with all the numbers can help you there.
The two B+ leads are there to be able to choose which one is more suitably located for your wire set-up, so I was told. D+ is where you hook up the charging ligth, just like in your bug (blue wire of the bug).
D- (brown), D+ (red) and DF (green) are needed to go to the regulator. These wires probably are already in your bug, as 1974 was the only year with an external regulator !
Good luck.
Walter

Disclaimer:
I take no responsibility for any mistakes in the above directions, which are just meant as a suggestion.
(sorry for this, but this seemed to be neccesary today and electrical porsche parts are expensive)

[samcat]

Thats IDENTICAL to mine,

You need an external regulator.

If you cannot get any more help I can unbolt mine and draw up a wiring diagram for you... Might be worth getting some wiring diagrams on the site's tech section.

Email me if you need it, it would be next weekend that I would do it (not enough light in the evenings at the mo)



Sam C

[Sandeep]

Thanks for the input fellas,

I do have an external regulator (stock) in my 74. I checked the wiring I had closely and it seems like I have the proper wiring. Now its a matter of extending the wires and then hooking it up. I will do it this weekend and hope for the best !

Sandeep

[Wally]

Sandeep,
You don't have to hope it goes well, it will, its simple, the colour coding is what makes it easy. Just get the proper regulator that came with the alternator. Don't use the bug's one. It will work fine the first few months, maybe year, though, but your alternator diode bridge (the expensive electrical part inside) will live much longer with the proper voltage regulator and then I won't have to tell you I told you so...
Just my 002 cents.
Walter

[Sandeep]

Thanks Walter !

I will take your advise and will source the regulator from the local porsche wrecking yard this weekend.

Sandeep

[lightning bug]

How about the Pelican Parts electrical diagrams? They might help you.

[kdanie]

Sandeep, Talk to Fat Performance, they have the solid state regulators at a reasonable price and can tell you exactly how to hook it all up.
ken

[Wally]

Ken,
Talk to a real electrical/alternator specialist and they'll tell you the solid state regulator thingies are cheap crap!
Walter

[Shadowbug]

it just so happens that I wired mine up today.

you need an external regulator, I have a wiring diagram somewhere I'll try and dig it up

(all but Red go to regulator) ...
Red 12 ga B+ Hot Goes to main power terminal on your starter(which is direcly connected to the battery)
Brown 12 ga D- Right post on regulator
Black 18 ga DF Center post on regulator
Blue 20 ga D+ Left post on regulator

there is a wiring Diagram here alternator is #3 regulator is #4

[Shadowbug]

how is this coming along?

[Sandeep]

The wiring went well but I can't tell if it works or not because I can't get the #@$% car started !!

I will add more to this thread when I get it started.

Thanks for all the help everyone.

Sandeep