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73 Javelin won't charge until I blip the throttle

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70amcpwr View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 70amcpwr Quote  Post ReplyReply Direct Link To This Post Posted: Jan/19/2015 at 7:54am
Originally posted by FuzzFace2 FuzzFace2 wrote:

Originally posted by 70amcpwr 70amcpwr wrote:

Whoa......lets go back to the beginning. This was a 73 Javelin AMX....Alt gauge...Motorola alternator that was rebuilt.......requires revving to engage. Somehow as soon as GM is mentioned that's where everyone went Wacko.
Where does it say Motorola ALT?
Originally posted by dsm6678 dsm6678 wrote:

Hi! This is for a 1973 Javelin AMX

My setup is the go package guages so I do not have an ALT idiot light


I got the alternator (NOT ORIGINAL) rebuilt for my 1973 Javelin AMX and the alternator will not put out a charge until I raise the rpm's up above what the fast idle cam is set at during cold start warm up period. I think the correct term is the field coils will not excite until I get the rpm's above a certain point


Also I have an AC/Delco alternator that does the same thing


This presents two problems for me. One I have the electric choke connected to the "F" (field) terminal on the alternator and unless I blip the throttle the electric choke is NOT working. Two If I blip the throttle to get the electric choke to work the fast idle cam is disengaged. So At that point I have the battery charging and the electric choke working but the fast idle cam will be disengaged..


Anybody have any idea on why the alternator won't charge unless I blip the throttle?


As for hooking up the electric choke to the feild terminal I read a lot of posts and apparently that is what the old timers did back then if there is no "S" termianl or "AC" terminal on the back of the alternator.



I really want the electric choke to work correctly it's looking more and more I am going to have to find a motorolla alternator with the AC terminal..


ANY info on this? I would be thankful,


D
He said "alternator (NOT ORIGINAL) rebuilt" and also said "I have an AC/Delco alternator that does the same thing."
So how did he try the AC/Delco if he was starting with the Motorola set up?
Any way I would think he needs to recheck wiring why he is not getting power to excite the ALT to start charging or wire in a light bulb so it will.
Dave ----


Sorry if I came across wrong.....sounded to me like he was talking as factory equipped with the option to go GM. Either way. Assuming with his as with my sons, this problem "occurred" and hasn't always been the case. Our sons is a Go Pack car, all wiring original and the problem began 1 1/2 years after the restoration.



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SOLD 1970 BBO Javelin, wifes 73 AMX 360 4spd. Next project 1969 AMX
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Post Options Post Options   Thanks (0) Thanks(0)   Quote dsm6678 Quote  Post ReplyReply Direct Link To This Post Posted: Jan/19/2015 at 8:49pm
Ok let me clear this up and sorry if I was not specific enough.. Originally my car was setup with a 2bbl carburetor and from what I have read in the service manual the 2bbl does not have an electric choke and also in the electrical part of my service manual it shows that some motorolla alternators DO NOT come with the "AC" terminal.
 
The alternator that I got rebuilt was NOT a motorolla I don't even know what brand it is it was in the car when I got it many years ago..  So I decided to get n ac/delco alternator from rock auto and it does not have an "AC" terminal either for the electric choke.
 
Yea so I wish I could just buy  a 51 amp motorolla alternator with the "7V AC terminal" and the choke should work just fine but they seem to be very difficult to find. I found a NOS one on ebay and they wanted $500.00 for it.
 
Anyone selling a 51 amp motorolla alternator with the "ac terminal"   LOL!!!!!!!!!!! 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote vinny Quote  Post ReplyReply Direct Link To This Post Posted: Jan/19/2015 at 9:43pm
just a thought but couldn't one use a resistor to get the volts down to 7? I would think that a wire to the choke with an inline resistor from the ignition might work but just guessing because I don't play around with this stuff very much. Or find a choke that likes 12V. 

As far as the alternator not charging I recommend again to use a Delco CS130. With the PLIS connector I think the P has something to do for a tach and usually is not used. The L goes to the lamp and on AMCs that wire is usually orange. If there is no lamp wire I think you can use the I to ignition. S is used for sense and can go directly to the output post as seen so often on the GM cars they are supplied on.   
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Post Options Post Options   Thanks (0) Thanks(0)   Quote dsm6678 Quote  Post ReplyReply Direct Link To This Post Posted: Jan/19/2015 at 11:18pm
Originally posted by vinny vinny wrote:

just a thought but couldn't one use a resistor to get the volts down to 7? I would think that a wire to the choke with an inline resistor from the ignition might work but just guessing because I don't play around with this stuff very much. Or find a choke that likes 12V. 

As far as the alternator not charging I recommend again to use a Delco CS130. With the PLIS connector I think the P has something to do for a tach and usually is not used. The L goes to the lamp and on AMCs that wire is usually orange. If there is no lamp wire I think you can use the I to ignition. S is used for sense and can go directly to the output post as seen so often on the GM cars they are supplied on.   
 
Just typed a lot of words and lost all of them I am looking into the idiot light. Anyone know the special wire connector I need for the idiot lights in the dash???? They are all the same from what I remember .
 
You know the little light bulbs that twist in the metal housing and then you have to have a wire under it with a spring?? or just extra pressure somehow????with a little metal ring???? that fits into that metal fixture where all the idiot lights are...
 
I have to take this apart again and see how they are in there all the idiot lights are connected the same I think I just don't remember the exact setup on how the wires are attached to the metal housing.
 
Yea I could just add the correct light bulb and solder a wire to it but I would like to have the correct connector ... Yea I have to take the dash apart again and see what exactly is needed and try to find the wire connector so if I add the alt light maybe the alternator will start chargiing right away so my choke will get power on start up.
 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote billd Quote  Post ReplyReply Direct Link To This Post Posted: Jan/21/2015 at 7:13am
I thought all AMCs had the light even when they had gauges. You might check again - bet it's supposed to be there. They used that to excite the alternators field.

(NO, GM ALTERNATORS ARE NOT NOT NOT SELF-EXCITING! There's too much BAD information out there about alternators in general, GM in particular, the info on Motorola is even worse. GM alternators are EXACTLY like all others, it's just that people who don't know any better choose to spread information based on guesses because "I once had a car that worked that way")

The bulb is like the others in the cluster unless somehow the 73+ Javelins are different for some weird reason.
The AMC system that uses Motorola has TWO circuits to excite the field. One is via the DASH light. That's why it's there even when there's a gauge package and because the wiring harness on that area is pretty standard regardless of options. AMC didn't change the main harness, they put in additional wiring and kept the same main harness so all connectors should be there.
The second excitation means is via the IGNITION coil.  The yellow wire goes to the coil AND the regulator. That way if the bulb burns out it's still got something from the ignition circuit. But if the bulb is burned out or LEFT out by an owner, AND the owner rewires the ignition system and uses a non-stock system, well....... no excitation!
The circuit using the bulb goes through the ORANGE wire. So it's ignition switch to dash bulb, out the bulb in the cluster through an orange wire and to the alternator AND regulator. The voltage is reduced by the bulb and is fed to the field to get it started or "excited". 
The circuit using ignition feed to excite goes through the exact same wire that feeds the coil, then to the regulator yellow wire. From there the ignition feed goes through an internal resistor in the regulator and out to the field or green wire. I believe it's probably a 75 ohm resistor inside, that's the approximate value of the resistor they used in the early 60s when it was a separate part.
When the engine starts and the alternator spins up that tiny bit of current through the field gets some output going - some of this is out via the orange wire at the alternator -  which is then used by the regulator to feed the field circuit and control output (orange going to regulator). When the output reaches regulated system voltage then it goes back to the bulb making it 12+ on both sides of the bulb, turning it off.
GM alternators work the same way but some folks have chosen to make them "1 wire" systems, a bad idea for cars. GM never sold them as single wire systems for cars or automotive, shade-treers and street rod makers did that likely after seeing how they were wired on tractors and industrial equipment when all they did was charge a battery and not all that accurately. GM used the same sort of terminals, feed from the dash bulb and so on and they again are not self-exciting. The rotor poles are treated so they do not hold residual magnetism, unlike generators. Oddly enough GM called them generators in the 70s. Delcotron, electronic generator, AC generator, etc are terms I've seen in their documents of the time.

Bottom line if you have to rev the system then either the regulator is bad or there's no dash bulb circuit (out the dash via the orange wire to the alternator and regulator) and there's also no feed from ignition.

NEVER EVER connect ANYTHING TO THE FIELD!! EVER! Period. No car company ever did this, none, not a one. No mechanic or tech would either. It's very risky to the electric system, especially the regulator.
Anyone who tells you "that's what the old timers did" is lying or a fool. Sorry to be so blunt but we fight that garbage daily. No, REAL mechanics who knew anything about electric systems would have cringed or yelled at the person who did that. You are sucking field current and totally messing up the regulator - even to the point of frying the regulator internally.
If there's an electric choke FIRST find out the voltage requirement for it! Some used 7vac, some used more like 12vdc. There's a difference. AMC used electric chokes in 1974 that used 7vac and it was fed off the negative diode array. There was an insulated terminal on the side where the negative diodes sit and it fed off that. It's possible to CONVERT, or I've got some "back ends", what Motorola calls "rear frames" from that era that can be used to make any 71+ Motorola alternator put out 7vac for a choke.
Other cars later used 12v from the oil pressure switch (sending unit is for gauges, switch is for lights but don't we all call them ALL sending units because that's what we were taught?  Wink  )
They used the OP switch because that way if the engine wasn't truly started and running there wasn't anything to heat and relax the choke stat. When the engine was running and there was oil pressure it closed the contacts and allowed current to flow to the choke stat which in turn relaxed the choke stat coil and opened the choke. This way you could have a key on for diagnostics work, etc. and not have the choke heated up on a cold engine.
They used alternator output for the same reason in prior years. So be sure the choke stat is what you expect - and you feed it what it expects, either 7vac or 12vdc.

There are at least 2 things you never do to an alternator system:
Never pull a battery cable when the engine is running.
Never connect anything to the field circuit.
Doing either can fry things badly and you may not see the smoke get out. It can be sneaky that way, it can leak out silently and since all electronics run on smoke, when the smoke leaks out they stop working. I've never been successful at getting the smoke back in, I think it's sealed in at the factory and they don't sell smoke injection systems that I'm aware of.

BTW - GM 10si - terminal 1 goes to the alt light, 2 goes to sense, should go to where the load is, like on AMC where the wires all connect at the battery side of the solenoid/starter relay.

Anyone have a correct AMC wiring diagram handy - didn't all models have the dash light for the alternator even with gauge package? Or am I incorrect?
My books and diagrams are all at home and I won't be there for at least 12 hours.

Oh, here's some facts on exciting alternators, specifically Motorola but is pretty well useful for others as well if you account for different terminals and wire colors.



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Post Options Post Options   Thanks (0) Thanks(0)   Quote 70amcpwr Quote  Post ReplyReply Direct Link To This Post Posted: Jan/21/2015 at 7:23am
Ok, not that this helps my issue any LOL. There's a wire coming out of the harness below the wiper motor, just before the bend in the harness, blue I believe, I don't recall it"s original purpose, maybe A/C related. Anyways it's 12v key on hot. It has a female bullet connector. I've used it for every electric choke installation I've done, just plug in and you're all set, works great.







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Post Options Post Options   Thanks (0) Thanks(0)   Quote bigbad69 Quote  Post ReplyReply Direct Link To This Post Posted: Jan/21/2015 at 8:38am
Originally posted by 70amcpwr 70amcpwr wrote:

There's a wire coming out of the harness below the wiper motor, just before the bend in the harness, blue I believe, I don't recall it"s original purpose, maybe A/C related. Anyways it's 12v key on hot. It has a female bullet connector. I've used it for every electric choke installation I've done, just plug in and you're all set, works great.
That wire is probably the power for the kick down on the automatics. It's left hanging on stick cars. I used it for an electric choke also.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote dsm6678 Quote  Post ReplyReply Direct Link To This Post Posted: Jan/21/2015 at 8:58pm

I remember that wire on my 70 javelin 4 speed manual shift car . I was wondering what that wire was.

 


Edited by dsm6678 - Jan/21/2015 at 9:15pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote dsm6678 Quote  Post ReplyReply Direct Link To This Post Posted: Jan/21/2015 at 9:11pm
"I thought all AMCs had the light even when they had gauges. You might check again - bet it's supposed to be there. They used that to excite the alternators field."
 
Hi Bild. I am looking at the wiring diagram at the back of the service manual and also at the wiring diagram for the optional guage pack under the electrical chapter of the book..
 
The wiring diagram at the back of the book shows the "alt" bulb and orange tracer wire to the alternator BUT........
 
From what the book is showing under the optional guage wiring diagram in the electrical chapter is that the orange tracer wire and the "alt" bulb  are not there when you have the optional guages
 
The service manual is showing NO idiot light with optional ammeter guage.
 
Hey you could be right about having that idiot light with the ammerter guage but the book is not showing it. I could be reading the book wrong 
 
thanks for the information I better look into trying to find a motorolla alternator if I want this to work and possibly add the "alt" light
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 70amcpwr Quote  Post ReplyReply Direct Link To This Post Posted: Jan/22/2015 at 7:45am
My memory was a little off, blue w/tracer. I used that wire on the BBO Javelin that is an automatic, kick down is hooked up and works fine.





Edited by 70amcpwr - Jan/22/2015 at 7:48am
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