charging blues

[Patronus]

First off, I have been reading threads on this subject for hours, and my head hurts.  
Im not very elect. savy and really need some help. Last night was the first time I drove with headlights, and it drained the battery in about 2 miles. Its a new alternator and has 3 wires. 2 go to the post and single green to tab. I've seen Nachos thread on a re-wire but find it extremely hard to follow. Does anyone have clearer instructions on what I believe to be the bulkhead bypass?
Also: fyi: multimeter reads 12.82 sitting
                                      12.55 running
                                      12.22 running w/lights
those don't seem right

[Nacho-RT74]

at the end only thing you need to make is open a hole on firewall and run new wires from alt to ammeter and get back from the other ammeter stud to starter relay, thats all.

Check the ammeter for loosen terminals... that could be a reason, then the bulkhead terminals

[Patronus]

I cleaned up the v. reg. mount and checked firewall connections. Still only 12.5 v running. I have the alternator wired with a black wire and a purple wire wired together to the stud on the alt. and then a green wire with a tab connector to a male prong. Does this sound right? Its a NAPA alt. I also have the small style voltage regulator, should I be using the larger Electronic voltage regulator? Is there a way to test it?

[Nacho-RT74]

I'm talking on back of cluster at ammeter studs ... also terminals at bulkhead.

yes you have it wired right. violet is the hot source to horn relay up to 69s mounted at radiator core support. On 70 were changed to inside the cab

black is the alt output

green is the regulated field coming from regulator.

[A383Wing]

you don't say what year car....and why do you have a black & purple wire to the alternator main batt terminal??

12.5 would indicate to me that it ain't charging....either something is wired wrong, or possibly regulator or alternator is bad

[y3chargerrt]

Can't really tell but is the second field terminal grounded at the alternator?

[tan top]

you don't say what year car....and why do you have a black & purple wire to the alternator main batt terminal

thats the stock set up black & purlpe wire to the alternator power stud, the purple  wire takes power to the horm relay

Can't really tell but is the second field terminal grounded at the alternator?

thats what i'm thinking  , got a better picture ??

[Nacho-RT74]

is roundback... unless is a 70/71 alt whih got 2 prongs, this should be only one prong kind which is the one what gets the wire from regulator.

the other brush is attached directly to the chassis. IF THIS BRUSH HAS A PRONG, needs to be grounded. You can replace the isolation washer for a metallic one, and cut the prong to save from wire this one accidentally.

OR ground it with a wire to the chassis, just that the first option I say gets a cleaner look.

or IF this alts is two prongs, you can convert to lates electronic regulator. Is an easy installation, an splice to hook the regulator plug, and a new wire running to alt

[Patronus]

Thanks Nacho, yes from what we've found out it is the wrong alt.

[Patronus]

Here's the old one I took out and the new one. I don't really see any difference?? I don't think I have it hooked up right. I only have those two connections, the black/purple and the green. Am I missing something?

[tan top]

  thats odd looks like someone  has tried to turn a single field alternator  it to the later square backed duel field  
 what was the reason you was changing the alternator ?  have you done any wiring work ? did you buy it like this  ?? what type of voltage regulator have you got  has it got modern guts in side ??

[Patronus]

Hey TT. I was changing the alt. just to clean up the engine bay and kept it for a spare. I haven't done much wiring, just got rid of the elec. choke. I have the older voltage reg. (see pic). So do you think both these alts. are wrong? I bought it with the older alt. it ran fine, but I didnt really drive it much. What alt. should I run? Pic? Model #??

[Nacho-RT74]

ok... the one of the top, THE PRONG ADDED DOESN'T MAKE ANY SENSE!!! THE BRUSH IS ALREADY GROUNDED BEING DIRECTLY ATTACHED TO HOUSING. Also, you can wrongly hook up the green wire there, what on old regulators kind, drives POSITIVE so one you put the key in RUN will be shorting out.

On second one, it is in effect a 70/71 round back alt used to be match with electronic regulators. The prong at 12 o'clock was cut what is nice to save from wrong wire hook up and cause a short once grounded, but then NEEDS to be grounded. You can replace the isolation washer underneath the retaining screw, using a REGULAR STEEL WASHER, and done! you'll be grounding the brush to get the negative field liek earliers did. The isolated prong will get as must be the green wire getting positive from regulator and VOILA! magnetic fields are both inside the alternator to create power.

[Patronus]

also, I put the old one back in and the alt. gauge reads much steadier, yet at idle shows -5 and +5 at about 2000rpm. Multimeter still only reads 12.6 running...  

[Nacho-RT74]

OR you can modify your system to use later regulators... one wire added up to alt ( blue ), get back an untouched brush prong, keep the isolation washer, couple of splices to the regulator pigtail and done.

Note, these alts are not quite efective under low RPMs

[Patronus]

Thanks Nacho, I know you can help, if I could just understand your typing... so I will reinstall new alt. (lower in pic) and hookup like I had it, but will have to remove the rubber washer under the other prong and replace with steel?

[Patronus]

this?

[Nacho-RT74]

sorry if my typing is not easy to you... if there is something you can't understand let me know. Being the english not my mother language and using english just here on boards sometimes I don't take in mind what mistakes I'm making.

Yes, you need to ground that brush. Use a metallic washer instead the plastic, rubber, bakelite or whatever isolation  materiall for the washer being used there will make the job.

That washer normally attachs between screw and prong, not underneath the plastic housing

You also can bend what still rest of the prong below the isolation brush housing and will help even more on a good ground.

with that alt, you can also upgrade for later electronic regulation system whenever you want, just replacing that cut brushed prong for a new one and getting isolation washer back, ( so don't trash the isolation washer just in case ) and getting the newer regulator, pigtail and extra wire

[Patronus]

Please Nacho, no need to apologize, if anything I should, as elect. is a foreign language to me. (I am willing to learn though.)
I have the older alt installed and quickly ran a wire from the additional prong to the chassis with no change in readings.

[Patronus]

Given the choice I would like to run the newer alt. Although personally, I can't really tell a difference. On the new one both prongs have FLD next to them. On the one I removed (pic w/ washer) it does not have an isolation washer on top of the cut prong, only the one under coming into contact with the housing. Im not too concerned with original so... were I to reinstall newer alt. and ground wire to chassis from said brush I should be ok? I dont think this thing was ever right, please, let me thank you guys for your patience. Someday I might have 14v...

[Nacho-RT74]

the washer was installed wrong, simply that.

No need for a wire if you install the metallic washer on the right place. The ground provided by the screw into the alt chassis and then making contact with prong through the metallic washer is enough.

if you want extra added ground, bend what still rest of the prong underneath the brush isolator and will make even MORE chassis contact.

the advantage of newer regulators Being electronic is they are less noisy to electronic ignition modules, against the mechanic relay kind old regulators.

NOTE... hard to reach 14 Volts from these charging systems... 13.5 is good anyway

[Patronus]

I will reinstall the new alternator with a washer on top to make sure we have a ground. I will check to make sure with a test light from the pos of battery. (This is basically how I had it before.) 

[Patronus]

Well, no luck. I have a ground at that brush but its still not charging. The only time I had a reading on the plus side of the interior gauge was with the old alternator. Yet even with that its still only 12.5 v. Im guessing a new voltage reg?

[Nacho-RT74]

feed the field at prong with 12 volts to check what you get... that will make FULL FIELD ( bypassing regulator ) so don't rev up the engine

are you sure you have clean bulkhead terminals and clean and tight ammeter wires on back of cluster ?

[Patronus]

So I will start the motor and use my test light from pos of battery to alt. stud and then check battery with meter?

[Patronus]

correction: from pos of battery to green wire prong?

[Patronus]

I still only get 12.5v Guess I will just run the old alt. since its the only time I have any + reading on the dash gauge. I have a friend with a 71 Demon and he ran a large gauge wire from alt. stud to pos of battery, would this help me?

[Nacho-RT74]

yes from batt to green wire prong, that makes a bypassed regulator

what about ammeter reading with regulator bypassed ?

try to rev it up a little bit

have you tested the output directly from alt post instead batt ?

[Patronus]

no change, just -5

[Patronus]

12.5 at battery, 12.2 at alt. and never any change at the gauge with the new alt.

[Nacho-RT74]

welll I it think worths try change the regulator, but weird being you are bypassing the reg with that wire.

AND CHECK the bulkhead plugs and ammeter studs!!!! Dunno why I think there you could find some problem

[Patronus]

I just wanted to give thanks to Nacho and you guys for trying to help a brotha out. Looks like both my alternators are wrong. Check this out though, the newer one was bought at least a year ago during the resto. NAPA says they will exchange it for the single field they had to dig up in Minn. So thats cool! I dont like having a crappy old charging system, but lets face it, this shit is $$$! Someday a nice modern one wire, amp gauge bypass and that headlight rewire and I'll be set. 

[Nacho-RT74]

I was afraid to say a bad alt being new, but everything was pointing out to that... or bad contacts somewhere. The full field test getting just that juice was a definitelly THE test for it.

no need for gauge bypass but its on each own

[Patronus]

Here's something I dug up: http://www.4secondsflat.com/regulator_tech.html
Im going to upgrade to Elect. VR, yet I cannot find the wiring harness, Nacho?

[Nacho-RT74]

with that regulator you won't need to go to dual field or modify harness... thats an electronic reg based on single field system. Its a plug and play job

[FLG]

From the pic its clear your not going for an OE look, so why not get rid of all that external regulated stuff and just go with a 1 wire GM alt? Also tends to eliminate that idle charging issues with these mopars. Also if things go wrong its a heck of a lot easier finding a parts store with a GM alt than a mopar alt.

[Cooter]

From the pic its clear your not going for an OE look, so why not get rid of all that external regulated stuff and just go with a 1 wire GM alt? Also tends to eliminate that idle charging issues with these mopars. Also if things go wrong its a heck of a lot easier finding a parts store with a GM alt than a mopar alt.

Amen...

[Patronus]

Sure FLG, Im down. I have this alt. and I dug up a elec. VR, but you're right, I should probably get rid of that crap. Im not too sure on which one though. Which amp would you guys recommend? Also, Im assuming I can just modify my brackets? (I will also upgrade the wiring)

[Nacho-RT74]

any delco alt will be better than the originals ( even the 60 amps ones LOL ), just for ONE REASON, the winding design ( Delta kind ) is able to capture more magnetic field so will have more power at less RPMs what is the originals alts will have ever.

In stock form our cars doesn't need more than 60-70 amps source. Even with headlights upgrades halogen or HID and stereos. Demand is increased with cooling fans, when an 80-90 amps will begin to be mandatory.

you can CHECK the "no need more than 60/70 amps REQUIREMENT in our cars" ( being stockish ) thruth, simply reving up the engine and turning all the stuff on car, and will notice the stock alt ( around 50 amps ) feeding the full capacity will show practically center needle at amm, as far battery is also full or close to that.

In both cases charging wiring upgrade will require to be upgraded proportionally. Parallel up to ammeter, or ammeter bypass, at your choice. As I have told ammeter bypass is not really required as far everything is sourced from the right side and the source ( alt ) is stable, being just critical in case of an alt fail, what anyway if it happens reduce the electyrical load ( tunring of any accesory ) is mandatory no matter what alt, batt or existing or not amm, up to get to a place to fix/replace without damage the batt once is death.

in any case, if you will replace to a higher amp make the 80-90 amps jumps it adviced thinking on future upgrades. An 80-90 amps alt won't mean will feed 80-90 amps, will mean IS ABLE to feed that. The alt allways will feed JUST THE CAR DEMAND. You can get a 300 amps alt but if car demans just require 40 amps, the 300 amps alt will put out just 40 amps. A 300 amps alt will become dangerous on a death battery though, what will suck all what the alt is able to give, and not dangerous for the alt, really for the wiring and contacts

[Patronus]

Well, I had the new VR and dug up the old harness, so I will try that newer alt. again. Just to see since I have the parts...
The old reg. has grn/blu wires and then grn FLD wire, how should I hook up the new one, it has a grn and blue. Thanks

[Patronus]

This is probably not worth it I know... 

[Nacho-RT74]

you mean to convert a single field on to a double field system ?

( and of course both brushes isolated from chassis )

Brushes are cheap

[A383Wing]

from what I have heard & read...converting one of the old style single field alternators to a dual field may not work all that well.....I heard that it don't charge as good as the "square back" OE style dual field ones

am I wrong?

[Nacho-RT74]

yes I think you are wrong LOL.

alt capacity is fairly the same between round and squarebacks alts, the diff is the electronic regulator is more effective.

He will be recoverting back the dual field setup on a 70/71 roundback he had converted to work like single field.

the extra advantage on squarebacks is the diodes keeps cooler on them by design

[Patronus]

I keep getting grounded readings on both the green and blue @ the alt, Im still only getting 12v..
I may be done with this. Thinking: http://www.summitracing.org/parts/PWM-74191/
If I run this, its just a wire to the battery and then no more external VR? Will I still need the ballast resistor?

[Nacho-RT74]

ballast resistor is for ign system not charging system.

are we sure regulator is getting 12 + volts from ign switch?

dual field you should able to test 12 volst between both wires ( green and blue ), single field you should be able to read 12 volts bewteen green wire and ground ( with ign key in RUN )

this is really weird. If you full fielded brushes ( one with + and the other with - ) on back of alt, there is not option, something wrong still with alt

[Patronus]

Nope. I just tried a square back off another car, its still only 12v...
its not the alt, its not the VR, amm gauge, firewall connector, cables, grounds, its a mopar.

[Nacho-RT74]

did you full field this new one ?

have you tested directly at alt stud ?... make the test without hook up the main wire to the alt ( isolate the wire for safety )

[Patronus]

yeah, on that alt. I did isolate the other field wire and soldered a tip on. I just checked it w/o the main wire hooked up and its less than a volt. running.

[Nacho-RT74]

damaged alt, there is not other one.

shorted or broken windings on rotor, shorted stator ( stator is hard to be broken ), some of the diodes banks... there is not some other reason. You have not other search than inside the alt

It could be the brushes tracks at rotor, unsoldered or broken tabs from rotor windings

[Patronus]

Thanks for your help Nacho. Its not the alternator, I just put the last one we used for test back in and it checks 13.8v
I have some misgivings about the fusible link from starter relay to bulkhead connector. I should replace it. I've seen no real way to remove it from the connector though.

[Patronus]

let me add fusible link to the list...

[Patronus]

Read this: "Basically, a wire is added to the second Field brush on the alternator. On the orignal alternator, this brush is grounded to the case of the alternator, so you'll need to either change the alternator to a 1970 or new style, or adapt the newer brush set to the old alternator. The brush set costs about $5 at your local parts store. The second field wire is connected to the outside plug on the newer voltage regulator. (two plugs, one is in the middle, one is on the outside). The original field wire that ran to the "FLD" plug on the original regulator (green wire) needs to be connected with the wire that ran to the "IGN" side of the original regulator. This wire (both the old FLD and the old IGN) need to be connected to the center plug on the newer regulator as well. One other important thing is, the new regulator must have a good ground (-) signal to its case. Mount the new VR to a fender or the firewall and be sure to sand a little paint off the fender and the case so you have a good ground. If there isn't a good ground to the new regultor case, the charging system will not work properly!" This says the IGN "AND" FLD wire run together to the new VR, not just the GRN FLD. So then the blue wire from new VR runs by itself to the other prong on alt. correct? Nacho, you have it drawn IGN to BLU, FLD run alone.

[Nacho-RT74]

Blue wire of RUN circuit feeds EVERYTHING on engine no matter the model. You have a main splice to feed everything from there under the harness tape on later models due the several devices added allong the years OR running splicing wires from terminal to terminal due the lack of devices, like on earliers where you have just the regulator and ballast to feed, thats all.

This includes BOTH regulators requiring 12 volts from ign switch ( earliers and laters ) and also the brush JUST on laters 2 fields. The laters VR doesn't send the signal to the field on blue wire, just turns on the regulator to makes it work. The field on alt being feeded by a blue wire just get full 12 Volts + lead from ign switch same as the VR itself

The the GREEN wire is the REGULATED source coming from regulator itself, no other source, no matter if + or - lead. On earliers with a grounded brush and old kind regs, the signal on wire is POSITIVE. On laters with both brushes isolated and flat laters reg and rubber plug, the green wire is NEGATIVE, regulated, but still negative

[Patronus]

A little update: got another alternator from Summit, a one wire with internal regulator. Pretty nice, 75 amp. I have it hooked up and have 13.9v at the battery! FINALLY!!    It was going good and then the new 8g fusible link I soldered in from starter relay back into the bulkhead connector blew, it was only a 20amp fuse though. I have the alt. wired with a new 8g wire to battery with a 50amp inline fuse and the original black main power feed from alt. to original harness. So what amp fuse should that fusible firewall connection have? Should I be worried about too many amps now for the o.g. wiring??

edit: 20amp is holding for now

[Nacho-RT74]

which alt you got ? TuffStuff? Powermaster ?

The fuse link ( 8g ? are you sure?  ) blew due the low charge on batt and suking all the power alt was giving at certain RPMs, what FOR SURE was more than 20 amps LOL.

in line fuses are not recomended for automotive use on main line unless you overrate them to hold peaks ( very tipical on cars ), so fuse link is my advice. 14 Gauge is more than enough ( original is 16g )

the extra wire you fit to starter relay its bypassing the ammeter, now the main splice into the cab is being feeded from alt AND from BATT by both sides, two bulkhead terminals, and load being shared. Not my fav job, but helps, yes

the original wiring even without the new wire will hold the load since once the car charge is balanced and alt is able to feed the car, barelly will get high load peaks, untill you begin to add accesories.

remember you can get A 300 AMPS ALT if you want, but if car demans just 50, the alt will feed JUST 50, so the extra amperage able to give the alt won't be used EVER. Just if batt dies, could be increased

[Patronus]

Powermaster 74091. Good to know on the fusible, I will switch it out. Finally drove it, first time in 2 1/2 years, with the windows rolled up, cruzin at night, super clear new glass, ah man it was beautiful...