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one wire alternator

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BBO Steve View Drop Down
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    Posted: Sep/28/2017 at 7:46am
I have a new Delco CS alternator 120 amp to replace the original Motorola 55 amp on my Javelin. I know most of the wires don't get reused but my question is which pin on the alternator runs the dash light and which wire from the original wiring do i connect it to? This is a CS not an SI alternator and has 4 pins instead of 2 spade connectors.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Moffman Quote  Post ReplyReply Direct Link To This Post Posted: Sep/28/2017 at 11:55am
Originally posted by BBO Steve BBO Steve wrote:

I have a new Delco CS alternator 120 amp to replace the original Motorola 55 amp on my Javelin. I know most of the wires don't get reused but my question is which pin on the alternator runs the dash light and which wire from the original wiring do i connect it to? This is a CS not an SI alternator and has 4 pins instead of 2 spade connectors.


You sure it's not a CS130? Not familiar with a 120 amp version. You should have one pin out of the four that is larger depending on the year of it.

Still only use two of the pins, L is for the alt light and S is for main power.

Edit: I just learned that the 130 doesn't stand for amp but the stator size in mm, the more ya know.

http://www.mgexp.com/phile/40/208476/cs130.jpg




Edited by Moffman - Sep/28/2017 at 12:03pm
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BBO Steve View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote BBO Steve Quote  Post ReplyReply Direct Link To This Post Posted: Sep/28/2017 at 12:06pm
Alternator B+ post is the one going to the battery correct? I just run a jumper down to where the battery wire hooks to the alternator? Love Vanishing Point by the way.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote BBO Steve Quote  Post ReplyReply Direct Link To This Post Posted: Sep/28/2017 at 12:09pm
Also is the wire for the light the orange one or the orange one with the tracer?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Moffman Quote  Post ReplyReply Direct Link To This Post Posted: Sep/28/2017 at 12:26pm
Originally posted by BBO Steve BBO Steve wrote:

Alternator B+ post is the one going to the battery correct? I just run a jumper down to where the battery wire hooks to the alternator? Love Vanishing Point by the way.



Right it's the sensing wire, you can run a jumper but it's not the most ideal way to do it because you will be sensing the alternator output voltage not the actual system voltage.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Moffman Quote  Post ReplyReply Direct Link To This Post Posted: Sep/28/2017 at 12:28pm
Originally posted by BBO Steve BBO Steve wrote:

Also is the wire for the light the orange one or the orange one with the tracer?


Depends on the year, not familiar with the earlier javelins but for example on mine (71) it was a light blue wire but in 73 TSM it was an orange wire. Haha it's a great movie.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote billd Quote  Post ReplyReply Direct Link To This Post Posted: Sep/28/2017 at 12:40pm
The information is out here as far as which wires do what on the AMCs, and should already be here for the GM alternators as well. 
120 amp? Really? You have EFI, electric fans and 400 watts of stereo?

If you connect it "one wire" (and there is no such thing, really- check out many posts about that so-called topic) beware that it's far less than ideal. Will it work, yeah, but never ideal. 

Typically there is an orange wire (sometimes apparently blue) from the dash light to the regulator, then an orange wire from the regulator to the alternator "aux" or "reg" terminal. That feeds the rotor (field) and excites the field before it starts charging AND controls the ALT light on the dash. The yellow is a backup for the wire that comes from the dash bulb in case the bulb is burned out so there is still a way to excite the field and get it started charging. This is because alternator rotors are treated to not hold residual magnetism - and they otherwise either won't or may not start charging on their own without that field excitation. 
The "single wire" method was mostly for ag and industrial equipment that was started and then run at speed, not idled etc. There is no such thing as a single wire alternator, it's a way of wiring them. I don't give a rat's butt what the performance catalogs say or call them - it's a way to SELL, to MARKET and it apparently works (because no one really knows better)
Also beware - that unless you really REWIRE your car, that 120 amp alternator may fry things if something goes wrong. There's nothing there that will support 120 amps.
Further - unless you have modified the car to need that much it will be spinning a lot of mass unnecessarily as it will only put out what is needed - meaning if you don't have EFI, don't run high-draw electric fans and don't have a massive stereo system, 60 is more than enough for any AMC.
Only when you stack in high-draw accessories like electric fans, EFI and certain other things do you ever need that. And if you have added those things and you  NEED that much and that alternator is told to kick out that much, things are going to burn. 

So never add that much unless it's truly needed by serious modifications and never add such an alternator without rewiring the car as far as the wires from the alternator to the battery, from the battery to the cabin area/fuse panel, and beyond. 

I hate to see people burn things up because of adding something just for wow effect and not considering what they are really doing. 

There are a whole lot of threads on this very topic here as it's been a biggy for years. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote vinny Quote  Post ReplyReply Direct Link To This Post Posted: Sep/28/2017 at 2:28pm
I've taken them off at the junk yard originally wired by GM with the S wire directly onto the output post but prefer to get it closer to the fuse panel or junction block. Using the old output wire and connecting it to S works. Then run a heavier #8 from the output post to the solenoid or battery. From my experience Gm usually uses brown for the lamp wire and AMC orange with white tracer.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote BBO Steve Quote  Post ReplyReply Direct Link To This Post Posted: Sep/28/2017 at 4:15pm
I don't have a ton of stuff but will be adding. Right now the 55 amp needs to be 30 mph to get the light out even though at idle it says it's charging around 14 volt. turn on lights or radio and down it goes. The choice was replace with the same thing that makes no sense to me, the next closest thing i found was 100 amp but i had to find and change brackets and it was a delco also. This one may say 120 but who knows, I doubt its more then 100. but it required no modifications to my brackets or having to search for some different ones.  Moffman, where would the ideal place be to hook up the S pin? What color would the old output wire be?

Edited by BBO Steve - Sep/28/2017 at 7:47pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote billd Quote  Post ReplyReply Direct Link To This Post Posted: Sep/28/2017 at 8:57pm
Sounds like the 55 amp simply needs rebuilt properly. Not sure why replace with the same thing "makes no sense" as honestly they put out better at idle than the 10si ever did so you have to go to the later GM style to get the equiv of what Motorola did with less spinning mass. 

GM marked the amperage on the case, at least in the earlier models. If it's a 120 amp it came off a loaded later vehicle with injection, electric fans and more. There simply isn't the load on a vehicle to need that much without those items. 
Fuel injection requires a lot of CLEAN POWER. A less than good diode and it can throw injection systems for a crazy loop. 

Did you know that a person can mount a 62 amp Motorola on any Motorola equipped vehicle and change only the voltage regulator connection and use the later regulator?  I have also modified or perhaps I should say built Motorola alternators to 62 amp with the isolation diode so the early regulator could be used. (the later dual-diodes handle it easily and Motorola snuck in different diodes internally in later years but never changed the sales number)
I have also polished Motorola alternators to make them look like the fancy bright GM units the hi-perf boys sell street rod people. Man do they look SHARP all polished up with nickel plated fan and pulley. (but that'll cost ya)

You can run whatever you desire on it but do please be aware that your original wiring will suffer if that ever does put out over 60 amps.
I doubt the fusible link wire AMC used from the alternator to the starter relay would be happy with that much current. 
By the way - output wire is red - Be it AMC, GM or DeLorean.
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