Alternator Question

[Neogenesis]

Evening Everyone,

I'll just apologize first, I'm a Jeep newb here. I just picked up a 1976 CJ7 , which had a charging problem. The previous owner included a replacement alternator, however it's missing a post on the back. The post in question is the smaller of the 2, with the brown wire connected. My google foo is failing me, can anyone tell me what this is for?

I did end up replacing it with the one provided, and took it to the local parts store where they checked it and it is charging correct, they also could not tell me what is was for. I'm just really curious what it's function is.

Thanks!!!!!

 

[Hedgehog]

There are better generator guys on this board. Here's my take on the whole situation. Your replacement alternator is a "Single Wire Alternator". Some like it some don't. Why the dislike? to start your alt. generating power you need to blip the engine up over 1,100 rpms or so. 1,100 rpms is enough to kick the regulator into a charge mode. I can't quite remember but I believe the brown wire kick starts the coils into charging right away without the need to blip the engine up over 1,100rpm.

I like the single wire alt. It's simple and efficient to me. When I first started dealing with a new alt. With my wiring being less than in good shape, there was a lot of discussion on the proper voltage, wires being switched, and invariably those that found that their battery would be drained dead by the alt. drawdown, sometimes over night. So, a single wire system seemed like the proper or easy way for me to go.

 

[mstar]

I can add one other note. the two wire alt. is needed if you want a amp light on the dash.I have one rig setup with 2 wire w/ amp light and amp meter the other is a 1 wire w/ volt gauge only. personal preference I guess.I have not noticed the need to blip the throttle on the newer 1 wire unit on my '69 .I have had older units that needed that and it is annoying . mike

 

[Hedgehog]

With mine it needs the blip, but when the engine starts its almost impossible not to bump the throttle a little. Once mine starts charging it always charges, its not a matter of keeping the rpms up.

 

[JR74CJ5]

Yup - the other is the "tickle wire" I've heard it called... Tickles the alternator until it starts laughing (charging).

 

[mstar]

the term I have seen used in wiring diagrams is "exciter wire"

 

[JR74CJ5]

the term I have seen used in wiring diagrams is "exciter wire"

Thats it! Tickle... Excite! Hehehe

 

[gert]

Thats it! Tickle... Excite! Hehehe