Sigma alternator wiring

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chris1
Posts: 25
Joined: Mon Oct 19, 2009 10:19 pm
Location: Adelaide

Sigma alternator wiring

Post by chris1 »

I have a sigma engine (2.6) in my buggy.... and the alternator has not been hooked up since I bought it. I'm looking at hooking it up ASAP, but was not sure what wires it needs, and where they should go :P It is a Bosch alternator.
I've tried to get a pic of the alternator, but not sure how to get it on here :P. Can someone let me know how to put pic on here, or, I can email it if you give me an email address.... then, hopefully someone can tell me how it needs to be wired up :)

thanks
chris1
Posts: 25
Joined: Mon Oct 19, 2009 10:19 pm
Location: Adelaide

Re: Sigma alternator wiring

Post by chris1 »

ok...hopefully this works... :P
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chris1
Posts: 25
Joined: Mon Oct 19, 2009 10:19 pm
Location: Adelaide

Re: Sigma alternator wiring

Post by chris1 »

anyone? :P
I need to get this together ASAP... let me know if you need any more info/pics....
Cheers
SE Wagon
Posts: 83
Joined: Mon Apr 06, 2009 10:08 pm
Location: Adelaide

Re: Sigma alternator wiring

Post by SE Wagon »

Hi Chris

I can't help by telling you about mine, as I had it replaced with a larger capacity unit. Somebody else did the work, so I don't know what (if anything) might have been changed.

It looks like a fairly simple setup, with (I think) "internal" regulator (the black block on the left), main wire to the battery (formerly from the yellow connector on the stud - that's the alternator output) so I would guess the remaining wire is for the charge light on the dash.

The other device attached to the stud would be a noise suppression capacitor - leave it in place.

So.

Heavy wire (6mm^2 or more) from the stud to your battery - take care to protect this wire from shorting to earth.
"Normal" wire from the spade connector through the ignition switch (presuming you have one :D ), then through a 2 watt globe to earth/chassis/-ve - whatever you choose to call it. This wire is used to provide an initial excitation current for the field coil, and shouldn't be big - hence, this is one of those circumstances where "bigger is better" doesn't necessarily apply - 2W max is advised, and you may find the system will work without it.

I had a quick look at a GN schematic - that's essentially all it had, so I can't imagine your donor vehicle would've been more complicated.

Good luck.
(Formerly) 1984 GK SE Wagon
Kings, Konis, EFI, exhaust. Not much power. :( But it is red! :D And Sold...
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chris1
Posts: 25
Joined: Mon Oct 19, 2009 10:19 pm
Location: Adelaide

Re: Sigma alternator wiring

Post by chris1 »

Thanks :) really appreciate it, I will give it a go tonight, and see how it goes :)

Thanks again
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oldn64
Oldn Engineering
Posts: 377
Joined: Sun May 09, 2010 5:56 pm

Re: Sigma alternator wiring

Post by oldn64 »

Ok you have a two wire bosch alternator, and as described it will not be hard to wire up. Easiest way would be to wire from the bolt connector directly to the start motor bolt supply. This should then run to your battery. Next is the excitor circuit, there are two things with this. 1stly this flows both ways, it will start the alt initially and also display if the alternator is not giving enough charge so highly recommend a globe be used as an indicator.

You do have a third wire (whihc is invisable) which is the case. I recommend that you make sure the motor is well earthed and the alternator is therefore suitably earthed from the motor. Apart from this it should work a treat.

Cheers
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The way God intended it.....Chrysler for the win :D
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