Moparts Tech Archive
Who Has Info On A Dual-field Alternator Conversion?Who Has Info On A Dual-field Alternator Conversion?
Author Topic: Who Has Info On A Dual-field Alternator Conversion?
I am thinking of putting on a "squareback" alternator in place of my 40 amp."no charge at idle" original.
The alternator, itself, is a bolt on. For wiring info take a look at:
Just completed the conversion tonight on my 68 440 Dart, man what a difference...
Can this mod be done with the "old" style regulator(but has new electronic guts) succesfully?
I've got a newer alternator on the wagon, you just ground one of the field wires.
For a 69 road runner could you just buy the 70 harness that has the dual field.
I have not heard of the conversion using the old style case/new internals regulator. My guess is probably no. Trying it would probably wipe out the regulator at least.
I just run a wire from the 2nd field to a ground, works killer.
You can just install a new alternator, or you can install one in conjunction with a new regulator.
Then you can ground the second field terminal and use the existing regulator. If you haven't already, spend $10 on a new regulator. Most replacement regulators you get these days all have solid state guts (which is what you want).
Or you can install the later dual field regulator and wire it according to the instructions referred to in previous posts.
I installed one on my Charger using the first method.
You need to be careful with the extra amperage going through the wire hareness. Make sure your fusibile link is intact.
I have also installed relays on the headlamps to eliminate the routing of all that current through the bulkhead connector and switches. This alone does wonders for your lighting output.
And also make SURE the wires hooked onto the back of the amp gauge are in GOOD conidition and Tight.Charging system problems.... Help elec.
As I have mentioned in another thread, Saturday my charging system quit working at the dragstrip. We have ascertained that its not the alternator by putting a known good one on it and it made no difference. Last week I replaced the constant output voltage regulator because it went bad and was reading 16 volts while driving down the road. the new voltage regulator solved the problem. At the track saturday we tried jumping the voltage regulator and saw no change. Yesterday for grins, I put the old constant output regulator on. Same problem exists, the car is not charging. All connections seem to be good and the engine wiring harness is all new. Ground strap is secure, voltage regulator is grounded nicely to the firewall and I got on the creeper and inspected the wiring under the car. All looks undisturbed.
Help!! I am electrically challenged to say the least...
I think my fuse box is all one piece and made of plastic, so I don't think you would have lost ground by it coming loose--but yours may be different. But having it hang around may have pulled something loose. Do you still have charging current going through your ammeter? If so, I'd look there if everything else looks good.
Take a jumper wiree and jump across the 2 ammeter posts. If the ammeter is bad it won't charge. They had a habit of going out at times. This could have happened with the over charge of the costant regulater.
To build on Don's comments, loose ammeter connnections are often to blame for charging gremlins. Make sure your connections are tight and all the terminal are clean before declaring the gauge at fault.
Gary, Dean described the troubleshooting procedure he did at the track on the way to the Nomm show and I pointed out a couple other things that possibly could have been looked at, mostly in the way the regulator was being bypassed at the time. I can't go into every detail but this should be a start, at least.
From the back of the alternator case, jumper one field terminal to -, and the other to + (doesn't matter which one). Start it and observe the ammeter or voltmeter.
-if it charges, then either the regulator, the regulator ground or the regulator wiring (before or after the regulator) is at fault. Go to "1"
-if it doesn't charge, leave the two jumper wires in place and Proceed to "2"
1-check regulator ground by jumpering the case to battery -, or any known good ground. If it charges, there's the problem. If not, then you'll have to check everything you can find in the wiring harness that is connected to the regulator, start at the engine compartment and work your way towards the dash with your test light (key on).
2-Jumper the large wire between the alternator and battery (use a thick wire), and start it. Check charge at the battery with a voltmeter, should be 14+. If it charges, proceed to "A". If it does not charge, then proceed to "B"
A- Something in the circuit between battery and alternator is at fault, look at the wiring itself obviously, but also the bulkhead connector, ammeter, ignition switch, and everything else you can find that is in that cirbuit.
B- either the reman alternator is NFG (it happens), or the battery is incapable of taking a charge (borrow one from another car), or the battery to chassis ground isn't quite good enough (that can be checked with yet another jumper wire!).
Got a trunk mounted battery? If so, get some really long jumper wires!
I am thinking like Don1. I don't think the fuse box being apart will effect anything, unless it is pulled. I have had mine pulled apart for troubleshooting and it caused no problems. Jumping the alt. output with a #10 or #8 wire to the battery (or the fender relay if you are using the factory circuit) should verify.
I'm with Don1. Open ammeter.
Does a ground circuit even goto the fuse box??
It shouldn't matter if a plastic fuse box is mounted or not.
The ammeter theory sounds valid, I'd check it out.
Meanwhile, I think ZIPPY has some good pointers
Dean I am with you on this one, there are no ground circuits in the fuse box.
This is what I saw.....
"From the back of the alternator case, jumper one field terminal to -, and the other to + (doesn't matter which one). Start it and observe the ammeter or voltmeter."
We didn't try this, we took both leads to ground thinking they were 2 fields in parallel and were switched to ground when driven. I did see 7.XX & 5.XX volts there with the key on (leads open) with a digital voltmeter. No harm done, since it sounds like, according to ZIPPY's info, both 12v and ground would otherwise be provided and we just took both leads low.
"probe the wires and connectors in the regulator circuit looking for a dead one, or bad connection somewhere."
"We checked the blue & green wires that lead to the alternator for continuity and a short to ground and found that all wiring was good.
"2-Jumper the large wire between the alternator and battery (use a thick wire), and start it. Check charge at the battery with a voltmeter, should be 14+."
Russ (74DUSTER360) added this circuit in. I later saw 12v from the harness lead to the alternator (disconnected) and felt it the harness was good and that circuit was redundant so we took it out.
I can help you troubleshoot that if you like. BUT, I'd need to refer to the correct service manual for your car and then I could walk you through the whole process in laymans terms. There should be some form of a schematic in the manual to chase the electrons with.
Dean, Did you check to see if there was 12v. at the blue field wire with the key on? You mentioned checking the field wires for continuity and short to ground, So I was just wondering.
And I've been looking at a 71 service manual wiring diagrams. It shows the alt. b+ wire going to a splice in the I/P wiring harness that splits to go thru the amp. meter and back out to the fuseable link at the starter relay. The other wires go to the fuse box, ignition switch, horn relay and head light switch. So I would say that if you get 12v. at the B+ of the alt. that the amp. guage is good.
That curciut runs from the ignition switch thru the bulkhead connector to a splice on the engine harness that also powers the ballast resistor and voltage regulator. Might be the splice is bad or the bulkhead connector, I would not think it's the ignition switch but you never know.
Nice call Dr. Bill!! With key on, there is only .7v at the blue field wire! Think we may have isolated the problem... I hope.
I don't know if they are the same. But I do know that the blue field wire is the same and should not be that hard to trace as there is not that many wires running thru the bulkhead connector.
Yeah he has B+ at the big terminal on the Alt. Just not on the blue field terminal circuit. We'll trace it back....should be easy to find. Thanks
Never say it will be easy. My old boss use to get mad at me when I would say that. Sometimes it would come back and bite me.
One step closer to finding the problem. Glad to hear it. Those bulkhead connectors are notoriously a pain. While monitoring voltage at the blue wire and key on, wiggle/push the bulkhead connector.
If the blue terminal is supposed to be battery voltage (12v) then something is acting as a load (voltage drop). It could be worn/pitted contacts in the ignition switch or a shorted out ballast resistor?
What about making up another ring terminal (connect it to the alt. post) with a small lead that would go to the same terminal that the blue wire went to and see if it charges then?
I checked out this post, as I had had a similar problem in the past.
All I can suggest, is that was what worked for me.
Good Luck with it. I KNOW how frustrating it can be, and generally speaking, I don't mind electrical work, yet this one had me running around in circles for quite a while (a few months.)
Also, yes the Stock Fuse Box is in two pieces. They clip together. Unless the wies got stressed, I doubt that would cause a problem.
If you crawl under your dash with a flashlight and take a close look at it, the two halves have wire harnesses running from the fixed half attached to the firewall and the loose half that clips with locating posts into the fixed half.
Usually those connections are pretty secure and are not easy to get apart even when you would like them to be.
Thanks to all of your suggestions and an hour of "TAG's" time, I got my electrical problem (no charging) fixed.
does it matter which field the wires are connected to on alternator?
i am trying to solve my overcharging problem. i`ve swapped in a different alternator and voltage regulator and it didn`t make any difference. what would happen if i swapped the field wires? any other suggestions? i converted from single to dual field.
i just did my rewire on my challenger and it did not matter. Although going from a single to a duel feed i'm not sure as mine was already a duel feed.
i swapped them and it doesn`t make a difference, still over charging.
Get an underdrive pulley if you don't already have one, that should help.
yup its got underdrives.
65, I do not know about your car, but usually if you are overcharging, the problem lies in the wires. One of your field wires(most likely the green wire) is probably shorted to ground, this will full field the alternator and it will charge anywhere from 16v-18v. You can try to temporarily rewire the alternator without using the stock harness...if the problem goes away, then you need to trace the bad wire (shorted to ground) and obviously fix it. Just my $0.02 (see diagram below)
my volt meter crapped out on me so i don`t know exactly how many volts it is. the gauge in the car is a 3/4, a little less at idle. i`ll recheck the wireing tomorrow. i will be suprised if i find any problems, i triple checked the wires before i wrapped them all. but that where it has to be i`ve eliminated everything else.
Should be running 13.7 volts. Battery voltage charged should be about 12.4 or so.
ground that v-reg housing Good.
I think you'll find Maxwedge1 is right. In the past I've had to run a ground wire between the voltage regulator and the engine block or any other area that's a good ground.
I'd get or borrow a real volt meter and use that before trusting the guage. The alternator output is usually around 14.5 at the battery.
I converted to 60 amp dual field on my 66 Coronet years ago and was told to ground one field so I did. One field goes to the regultaor and the other goes to ground. It works fine. Using the old style regulator with the newer electronic internals.
Alternator bracket and pulleys for 440
Could I use a B alternator bracket and pulleys?
Pulleys yes - bracket no. The 440 is taller so the bolt hole into the head would not line up.
Hello. Swapping brackets and pullies is not a fun or amusing thing to do. It can drive you crazy. You can get brackets from Year One, Hoffman's Winner's Circle, and March Performance. There is also another man reproducing all the pullies. I believe it is Bouscellon Performance? Spelling may be off.
You cant really see it in this pick but my stock alt bracket has 2 holes in it as I use the lower one on my 383 low block but the upper one is used on the 440 raised block. This is the bracket for the alt top bolt the long one. So I believe this stock bracket will work wiht either one. Ron
hmm... I always thought the B and RB bracket was the same but there is a difference between a/c and non a/c.
There were a lot of difference between brackets and pullies over the years. I think AC components alone switched four or more times, with all sets being different.
383-man is right . The alt bracket has 2 holes in the top. one for use with the B- 383 block and one with the RB-440 block. Pullys are all the same i.e. non air vrs. air are different but non-air 440 and non air 383 are the same.
As Montclare pointed out, there were differences through the years. The early non-AC bracket (pre '70?) is like 383-man said, two holes so it will fit either engine. You need to be more specific.
For non ac apps in a 383-440 there are
as far as non ac pullies,