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electronic voltage regulator required with higher amp alt on my 68?

Started by grdprx, December 22, 2011, 07:08:50 PM

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nrt69

which is the output stud?
what voltage should i expect running/not running?

Charger RT

Quote from: nrt69 on February 22, 2012, 07:59:55 PM
which is the output stud?
what voltage should i expect running/not running?

The big stud is the output stud.
The voltage should be very close to the voltage reading at the battery. both engine off and engine running.
A fully charged good battery with the engine off should be about 12.5 volt. Charging voltage must be at least 1 volt higher. (13.5) but most look for 13.5 to 14.2 volt running.
The voltage difference between the battery and the alternator stud can be effected by wire gauge, amps in the circuit, wire length, and the quality of the wire connections in the circuit. (In this case bulkhead connection).
But to get you charging I would think a drop of .5 volt at the alternator stud will be good to get you charging.
What kind of volt meter do you have?
Tim

68neverlate

It's good if you could provide the exact readings for both running and not running at the alternator.  As was seen in grdprx's case, a .8 volt drop between battery and alternator output stud pointed to bad connectivity between the two (the most likely culprit usually being the bulkhead connector).  A poor voltage reading with engine running can point back to a problem with the alternator...

Interested to see what you get...   :yesnod:   

nrt69

running is @ 11 volts, but its jumping around quite a bit.
not running its @12.2 volts.

Havent made it under the dash yet to check the gauge. will do this weekend.

Charger RT


nrt69


Charger RT

you should take readings at the alternator then again at the battery both running and engine off to confirm the voltage drop is not excessive.

are you running the stock 1 wire field alternator and regulator? If so with the engine running. Take a voltage reading at the field wire on the back of the alternator with it still hooked to the alternator and engine running. post back with the voltage reading.
Tim

Also grdprx if when your bulk head connector is fixed and your if yours still does not charge this would apply to you to check.

grdprx

Thanks Tim, I'll check it out once I get this rewired.  Waiting for a bulkhead to arrive.

nrt69

readings are the same...unless im doing it worng but i dont think so.

checked the back of the ammeter. one of the connections is melted.

68neverlate

OK, we're getting closer nrt69...    :yesnod:

The fact that you have melted wires at the ammeter tells us that the wires have seen more current than they are rated for.  The good news is that it doesn't appear to have cooked your ammeter... at least not at this point.  Rest assured, it will cook if you don't do something about it... more on how to deal with that later below.  The further good news is that the melted wiring at the ammeter does not appear to be causing your existing discharge issue...  

It's looking more and more like it's an issue with the alternator.  The fact that, with the car off,  the voltage readings at the battery and alternator are the same suggests that the wiring between the two is currently not an issue, however, that can and probably will change... more on how to deal with that later.  For now, it appears wiring between the alternator and battery can be eliminated as a cause of the discharging issue.  So alternator... there could be a few reasons why the alternator is not putting out... incorrect installation (connections), bad voltage regulator, bad signal coming into the voltage regulator, the alternator itself may have an internal short etc..  So, a couple of more questions, some of which Tim previously asked:

1)  What make and type of alternator do you have (is it a MOPAR one wire, two wire, a GM one wire etc.)?
2)  What is the make and type of voltage regulator (is it a MOPAR points style regulator, electronic, etc.)?
3)  What is the voltage reading at the field terminal of the voltage regulator (engine running)?  
4)  What is the voltage reading at the ignition terminal of the voltage regulator (engine running)?
5)  What is the voltage reading at the field connection of the alternator?

What I suspect might be happening is that there is a problem with the amount of signal getting to the alternator... no signal, no power output.  The signal comes from the voltage regulator.  The 11 volts you're seeing at the output post of the alternator with the engine running looks to all be coming from the battery at this point... your car is essentially running off the battery.  The battery never charges, gets run down... eventually to the point where the engine won't run.    

Again, answers will help narrow down the problem.   :yesnod:

Oh, yeah, back to the problem of frying ammeters... if you want to avoid this, you'll need to do one of the following:

1) replace your alternator with a stock output alternator (max 46 amp).
2) bypass the ammeter with the wiring modification Nacho outlined (direct from alt to battery)
3) controlled, fused bypass(es) to limit current going through the alternator

Drawback to option 1 is that you are still likely to have a discharge issue at idle so a lot of guys don't favour that (having a higher output alternator addresses the low output at idle issue but can create a lot of wiring woes due to too much current in the small gauged factory wires).  Drawback of option 2 is that it renders the ammeter useless (it won't deflect the needle any more), so you won't know what state your charging system is in.  If you can live with either of those two drawbacks, that's fine.  If you can't, then you should upgrade wiring and modify your circuitry to limit the current going through your ammeter (option 3).  There are a few threads relating to that on the site that I can point you to if you'd like info on this...

As for addressing the melting wires between the alternator and battery (like the ones at the ammeter and at the bulkhead connector etc.) you'll need to replace that wiring with heavier gauge wires.  I would also suggest bypassing the bulkhead connector (for the two wires carrying the high current).  Either that or again going back to a stock alternator with stock output... which as I alluded to above is prone to discharge issues at idle.

Stay the course.... I can feel an answer coming soon!    :2thumbs:    

nrt69

very much appreciate the time and help here....

remember the alt, vot reg, and batt are all new.
alt has 3 wires going to it. two small, one large. it is part# 01-0153 from OReillys. My old alt was the older style Mopar alt corect for my 69. I think it was a 60 amps or less.
I got the volt reg from Oreillys also but i cant find the part # for it. my old one obviously wasnt the problem since there was no change when i replaced it a couple weeks ago.

i thought Nacho's "parallel" wiring still allowed the amemter to work??

i get out and check voltage at the regulator as soon as i can....

nrt69

not sure i was getting a good connection for the voltage checks at the volt regulator but here are the checks:

3. @10volts, but fluctuating alot between 4-10.
4. same as above
5. w/eng running: @10.7volts on both the smaller wires (not sure which one i was supposed to check)


also, forgot to mention that it seems my ammeter gauge has a thicker wire going to, and through, the bulkhead.

Charger RT

does the regulator have its 2 wires on the front of the regulator next to each other or is there one on each side?
Tim

68neverlate

Quote from: nrt69 on February 27, 2012, 09:52:47 PM
3. @10volts, but fluctuating alot between 4-10.
4. same as above
5. w/eng running: @10.7volts on both the smaller wires (not sure which one i was supposed to check)

OK, there's a couple of things that don't quite sound right here...    :scratchchin:

The fluctuating voltage at the field terminal of the regulator is normal (that's how alternator output is controlled), although the range seems to be excessively wide (especially on the high end).  As for your readings at the ignition side of the regulator, that should be a constant 12 volts.  The other thing that doesn't sound quite right is the alternator itself... I believe '69s came with one (field) wire alternators.  I have a '68 (which is the one wire system) and can't find a good wiring diagram for a '69 on-line so hopefully someone with a '69 will chime in here and confirm.  I'm pretty sure '68s and '69s were the same though...  :shruggy:

In the mean time, a couple more questions... has one of the field terminals on your alternator been grounded at all (a continuity check between each field wire to ground with all wires disconnected should tell you this)?  Where do the two field wires from your alternator go to?

It's feeling a lot like the alternator and regulator might not be correctly matched on your car.  Regulators in a one wire alternator system send a positive voltage (varying) down the field wire to the alternator while the two wire system receives full positive voltage (12 volts) on one of the field wires and that voltage finds it's way to ground through the other field terminal of the alternator by way of the voltage regulator (which switches that ground on and off).  In other words, the one wire alternators are positively regulated by the regulator and the two wire ones are negatively regulated.  This could also be why your regulator wire connections were melted at the bulkhead connector.  Let's wait to hear your answers first though before coming to any conclusions...    :yesnod:    

Tim, are those questions you asked about the regulator because you suspect the same thing?   :shruggy:

68neverlate

Quote from: nrt69 on February 27, 2012, 09:52:47 PM
also, forgot to mention that it seems my ammeter gauge has a thicker wire going to, and through, the bulkhead.

Forgot to respond to this part of your post... yes, those wires are heavier gauge wires, but they are still not heavy enough to handle the output of most of today's higher output alternators.  Those are the two wires that carry the highest current through the firewall (through the bulkhead connector) though...   :yesnod:

nrt69

as for them not being matched correctly; the problem just started after my new eng/trans was put in late last year and happened with my old alt and volt regulator before i just replaced them last month. with my old engine combot i noticed i had some "extreme" charging (ammeter needle was half way to the right) just before i started my eng/trans swap in early 2011 - but it was fine for many years before that. that couldve been because my alt and batt was almost 6 yrs old by 2011? i dont know.

ill check the 2 small wires on my alt but i think they are part of the wiring that goes through the volt regulator. youll have to tell me how to check for grounding on these wires.

the volt reg is two prong. two wires entering from one side, one wire enters from the ignition side.

i have a wiring diagram, ill check.

nrt69

wiring diagram only shows one DGN wire  :shruggy:
i have two (one might be DBL, hard to tell). its also hard to tell due to everything being wrapped in electrical tape but it looks like one goes to the volt reg as it should and ones goes to the bulkhead location that shows a/c compressor on my diagram, which is a DBL wire. (my car did have a/c at one point in its life)

nrt69


Charger RT

thanks for the pictures. your regulator is correct style for the year of your car.

The alternator is not. but that is just fine my 68 is set up the same. You said both field wires at the alternator were about 10.? volts. One of the 2 field wires on that style alternator needs to go to ground to work on your year car. The fact you said both were 10.? volt tells me there is no ground on the one that should be grounded.

unplug both off the alternator start the engine and check voltage on them while unplugged. 1 should have voltage the other should have nothing.

plug the one with voltage back up it is fine. take a look at where the other one goes. It should just run off to a ground somewhere. Or make a new ground wire and hook it up to the second field terminal and I bet it will charge then.
Tim

Nacho-RT74

I think we are getting closer... I have not read detailed every word on lates replies but as far I have read:

my "mod" yes, keeps working the amm. My suggestion about jump the wiring between batt and alt it was FIELD RELATED not output stud. That would make to work the alt at max output bypassing any wrire and connection around to know if you have the alt in working order and locate the fail anywhere else but the alt. Feed one of the fields from batt and the other one from any ground point.

about the ammeter melt... is just about clean from dust, rust the nuts and stud threads, wires terminals. Some dieletric grease will help a lot, conclusion: any mantenience related with electrical parts. maybe in fact replace the masonite or cardboard isolation piece. Return to the stock output alt is a big NO NO, since will get you on same failure in some years like originally did. This was in fact the reason why that happened. To save this only solution is in fact increase the alt to a bigger output one. That will keep the batt and ammeter allmost out of the power source game. With parallel wires the amm stud will become practically just on a "power buss". This is the moment will need to be kept clean and tight all terminals and nuts on ammeter. With the paralel wire, the main splice inside the cab will be feeded from both sides of splice, the section coming from alt, and the section coming from ammeter WHAT DOES NOT MEAN, from ammeter/battery, just from the new parallel wire.

to make work a dual pronged alt on a stock kind regulators ( mechanical or electronically upgraded internally ) need to ground one of the fields. My suggestion is replace one of the fields isolation washers for a metallic one and cut the prong you are grounding to keep safe of any plug confussion when hooking up the regulator. With this procedure you are converting a "dual field" into a "single field" which is the correct one to work with your existant regulator

you can also ground the prong with a terminal and an jumping wire to any alt case bolt BUT, that makes it look fuggly. Cut the prong for safety and ground the brush screw with a metallic washer makes a cleaner installation

Now, are you saying you have blue and green wires ? your configuration for the year should show just a green wire which is a regulated positive source coming from reg.

any other blue wire around, yes it can be the AC compressor clutch source.

If you have blue and green wires, and the blue one not being the AC compressor clutch you have something weird there AND a wrong regulator for that LOL

Venezuelan RT 74 400 4bbl, 727, 8.75 3.23 open. Now stroked with 440 crank and 3.55 SG. Here is the History and how is actually: http://www.dodgecharger.com/forum/index.php/topic,7603.0/all.html
http://www.dodgecharger.com/forum/index.php/topic,25060.0.html

68neverlate

Quote from: Charger RT on February 28, 2012, 11:39:41 PM
thanks for the pictures. your regulator is correct style for the year of your car.

The alternator is not. but that is just fine my 68 is set up the same. You said both field wires at the alternator were about 10.? volts. One of the 2 field wires on that style alternator needs to go to ground to work on your year car. The fact you said both were 10.? volt tells me there is no ground on the one that should be grounded.

unplug both off the alternator start the engine and check voltage on them while unplugged. 1 should have voltage the other should have nothing.

plug the one with voltage back up it is fine. take a look at where the other one goes. It should just run off to a ground somewhere. Or make a new ground wire and hook it up to the second field terminal and I bet it will charge then.
Tim

Yup, I agree.  If you ground one of the field terminals on the alternator, I think you'll be back in business...   :yesnod:

68neverlate

Quote from: Nacho-RT74 on February 29, 2012, 09:50:49 AM
my "mod" yes, keeps working the amm. My suggestion about jump the wiring between batt and alt it was FIELD RELATED not output stud. That would make to work the alt at max output bypassing any wrire and connection around to know if you have the alt in working order and locate the fail anywhere else but the alt. Feed one of the fields from batt and the other one from any ground point.

Hi Nacho... the mod I was talking about that might affect the ammeter was the one where a parallel, heavy gauge wire (shunt) is run between the battery and the output stud on the alternator to limit the current going through the firewall/bulkhead connector (and ammeter) when there is a serious discharge or charge situation (ex: the battery is really low or the alternator is not working).  I think it was talked about in this thread here:  

http://www.dodgecharger.com/forum/index.php/topic,61947.0.html

I had a chance to do a quick re-read on some of your other threads on the alternator output issue and realized that there are other variations of the modification that I referred to earlier in this thread (those variations are not shunts) that do not affect the ammeter, however, in each of those mods, it appears the ammeter is still at risk of being cooked (more than 40 amps which is the max rating of the stock ammeter).  If you don't ever have an alternator go down or charge a seriously low battery with the alternator in the car (ex: you charge the battery with a battery charger outside the car), then you probably won't have to worry too much about it, however, that means not being able to accept a jump in a parking lot after you've accidentally left your lights on.    

Gndprx and nrt69, if you get a chance, I would suggest some of these reads.  They show the amount of work Nacho invested in this topic and was gracious enough to share with the rest of us grateful followers!      :yesnod:   :2thumbs:

http://www.dodgecharger.com/forum/index.php/topic,33574.0.html

http://www.dodgecharger.com/forum/index.php/topic,62772.0.html

http://www.dodgecharger.com/forum/index.php/topic,61947.0/all.html

http://www.dodgecharger.com/forum/index.php/topic,6441.0.html

The first one above is a must read if you're not an electrical guru and want a basic understanding of what goes on in a our charging systems and what the basic issues are.  

Nacho, the suggestion you made earlier in this thread to take full battery voltage and put that to the field terminal of the alternator... I can see how that shouldn't affect the ammeter...     :2thumbs:    :laugh:    

(nrt69, this should only be done for a second or two (on a one wire alternator) to test that the alternator can produce maximum power...)

Cheers guys,   :cheers:

nrt69

ok , so im going to try and ground one of the small wire terminals on the alternator. im still a bit skeptical of this working because its basically the same set up ive had on the car since 1992 and ive never had a constant discharge state like i do now.

i had a hard time reading how to ground the alt. first, which terminal do i ground? i assume the one that is probably the a/c wire? can the volt reg wire that goes to the alt be plugged into either terminal?? second, i can either ground it with a wire from the terminal to, say, the engine block, or I can remove the terminal all together. is that right? im not sure what is meant by grounding it with a metallic washer but it will probably make sense when im looking at it. i assume removing one of the terminal is easy to do? third, to send full batt power to one of the field terminals (which one?) i simply run a wire from the field terminal to the batt? which side of the batt?

Charger RT

Quote from: nrt69 on February 29, 2012, 11:03:21 PM
ok , so im going to try and ground one of the small wire terminals on the alternator. im still a bit skeptical of this working because its basically the same set up ive had on the car since 1992 and ive never had a constant discharge state like i do now.

i had a hard time reading how to ground the alt. first, which terminal do i ground? i assume the one that is probably the a/c wire? can the volt reg wire that goes to the alt be plugged into either terminal?? second, i can either ground it with a wire from the terminal to, say, the engine block, or I can remove the terminal all together. is that right? im not sure what is meant by grounding it with a metallic washer but it will probably make sense when im looking at it. i assume removing one of the terminal is easy to do? third, to send full batt power to one of the field terminals (which one?) i simply run a wire from the field terminal to the batt? which side of the batt?

ok you sound confused. take a deep breath
the wire from the regulator can be plugged into either field terminal.

none of the wires for the A/C should be hooked to the alternator.

you posted " i can either ground it with a wire from the terminal to, say, the engine block, or I can remove the terminal all together. is that right?" yes the other terminal can be grounded with a wire just run to any metal ground engine block is good.

the term full field is a test people use to check the alternator on the car by eliminating the regulator for the test.
to make things simple it is removing both field wires then hooking two wires up to your battery one on the positive post and one on your negative post. then run those wires to the field terminals and hooking up one to each of the field terminals. This sends full battery voltage to the alternator with no regulation. The output can get as high as 18-20 volts. So if this is done it should never be hooked with engine running for more then a few seconds. Also the last connection should be made with engine running ready to check voltage and quickly disconnected. I don't think you need to do this.

In my last post I listed a way to figure out which wire is the regulator wire and which one is not.
With both field wires disconnected from the alternator. Read the voltage on each of the wires. The wire from the regulator will have battery voltage (10+ volts) reading. Just put that one back on the alternator. The other wire should read nothing disconnected. I would just push that wire off to the side and make a new wire run the new wire from the second field terminal to engine block, valve cover bolt or and good metal spot on the engine.
Tim


68neverlate

Yup, I agree with Tim, no need to do the "full field" alternator test right now... you have a new alternator so it's unlikely that it's a problem.  Just run the green wire from your voltage regulator to one of the field connections at the alternator and run another wire from the other field connection of the alternator to a ground and you should be good to go.  

I can understand why you might be concerned about changing the existing wiring, especially if you feel that "it worked before", but this is the correct way to connect it.  The wiring diagram bears that out...   :yesnod:

All that you're doing is converting the two wire alternator that you have to a one wire (by grounding one of the field terminals), which is what you need for your car.     :2thumbs:

It will all be good...   :yesnod: