One wire alternator.

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Doosterfy

Doosterfy

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I'm finally getting ready to purchase a one wire alternator. Powermaster has Mopar units that are converted to one wire units with a built in regulator. They have 100 and also 60 amp units. I'm tempted to go with the 100 amp one mainly to quicken up the battery charging at the track and also to brighten up the headLights and other illumination on the car. I am eliminating the factory amp meter and installing a volt meter. Are there other electrical items on the car that can't handle the additional amps? Would I be better off going with the 60 amp unit?
 
100amp would probably work but just keep in mind if your cars wiring is all factory....(and old) it was not intended to support a 100amp alternator per se. I'd go 60amp unless you plan on lots of upgrades (stereo, elec fans, fuel pump etc) and the requisite wiring upgrades (new/larger gauge etc). A relay kit for the headlights is a good idea! Those work great...it's up next on the list for my Duster. Using a bigger alt to brighten up the headlights is a little bit the "just shoot more ammo to hit the target" instead of better aim with one bullet approach. IMO...

Good luck! Both are good choices, and I'm sure some are running the 100amp with stock/old wiring without trouble but it's probably not ideal.

See Dan's (slantsixdan) expert and always entertaining opinion here (below)...and yes I dont know how to do cool embedded link on the word "here" like Dan does...but again, he's an expert. Maybe he'll chime in here re the alt question and destroy my only semi useful advice with a meat sandwhich of facts/links! Haha...

http://www.forabodiesonly.com/mopar/showthread.php?t=200609&highlight=headlight+relays
 
your accessories will only pull what amps they need to run on from the battery....

I have a couple of the powermaster one wire alternators in use....
 
Beatnik said:
100amp would probably work but just keep in mind if your cars wiring is all factory....(and old) it was not intended to support a 100amp alternator per se. I'd go 60amp unless you plan on lots of upgrades (stereo, elec fans, fuel pump etc) and the requisite wiring upgrades (new/larger gauge etc). A relay kit for the headlights is a good idea! Those work great...it's up next on the list for my Duster. Using a bigger alt to brighten up the headlights is a little bit the "just shoot more ammo to hit the target" instead of better aim with one bullet approach. IMO...

Good luck! Both are good choices, and I'm sure some are running the 100amp with stock/old wiring without trouble but it's probably not ideal.

See Dan's (slantsixdan) expert and always entertaining opinion here (below)...and yes I dont know how to do cool embedded link on the word "here" like Dan does...but again, he's an expert. Maybe he'll chime in here re the alt question and destroy my only semi useful advice with a meat sandwhich of facts/links! Haha...

http://www.forabodiesonly.com/mopar/showthread.php?t=200609&highlight=headlight+relays
Click to expand...

A one wire alternator does not use the factory charging system wiring...OnE wire...direct to the battery or starter relay battery terminal....does not go into the bulkhead wiring..
 
70aarcuda said:
A one wire alternator does not use the factory charging system wiring...OnE wire...direct to the battery or starter relay battery terminal....does not go into the bulkhead wiring..
Click to expand...


Uh................not quite.


It only hooks direct to the battery if YOU wire it that way. Some may very well hook it to the original charging wire.

I just don't like "one wire" alternators and no real reason to use them. You DO want to hook it direct to the battery with OVERsized wire if you want decent voltage sense

Also keep in mine that with a trunk mount battery you need to figure out a way to kill the ignition line to meet NHRA, IE use a 4 terminal, SPDT switch (It's not a "4 pole" switch)
 
Ok....thanks...i got mine hooked up and working...and yes it kills the ignition...

and i am only using a two post switch too..

DONE.....next subject...
 
70aarcuda said:
Ok....thanks...i got mine hooked up and working...and yes it kills the ignition...

and i am only using a two post switch too..

DONE.....next subject...
Click to expand...
no one mentioned that it would be getting rid of the stupid voltage reg. on the firewall. I`m going to run a 75 or 80 amp 1 wire, of course I`ve installed a new wiring system, only stock stuff left are the pigtails to switches - lights -etc., all new gauges, tail ight sockets etc. msd ign.
went w/ E Z wiring kit. any problems w/ their kit and u can call Sean for advice.
he is one smart sonofagun!----bob
 
Let's see, where to start...The reason for going to a one wire setup is to simplify things under the hood. I've used one wire alts on GM cars before and they worked good. The only drawback was that one has to rev the motor up to and RPM that turns on theialt, I.E. if you only start it at idle and leave it idling it will not charge. The last one I had I had to rev it to 3000 to get it going then after that it was charging at all RPMs. That is a non issue for me. The car is set up with a mechanical fuel pump, twin electric fans, MSD distributor, coil and 6AL box. No stereo or any other gadgets. I'm eliminating the factory bulkhead plug on the firewall and going with new 16g wires soldered and heat shrink wrwrapped at the splices. I'm making my own harness under the hood and the new harness will be spliced into the factory harness for lights, turn signals, etc. All wired going to the MSD, alt, starter relay will be new wires. The wires going to the tail light will be the original ones. I'm just trying to find out if there are items that will burn up and possibly cause a fire.
 
6. Install the charge wire from the alternator to the battery and make all connections.
· This is a “one wire” alternator, so the battery charge wire is the only connection required for
operation.

7· Powermaster recommends the battery charge wire be upgraded to an 8 AWG wire for the 140
amp unit and a 6 AWG wire for the 200 amp unit. Inline ammeters must also be upgraded to
handle the alternators rated power if they are to be used (Powermaster recommends that
ammeters be replaced with a voltmeter).

from powermaster instruction sheet...
 
70aarcuda said:
Ok....thanks...i got mine hooked up and working...and yes it kills the ignition...

and i am only using a two post switch too..

DONE.....next subject...
Click to expand...

So.............how did you "kill the ignition?"
 
I turn the ignition switch to off...and it dies...lol

the alternator wire goes to the battery side of the master cut off switch...
 
Doosterfy said:
I'm just trying to find out if there are items that will burn up and possibly cause a fire.
Click to expand...

The alternator itself can't do that unless something goes wrong, IE the regulator or fault internally causes the alternator to go to full output. A 100A alternator would be no small thing.

Or.......if the alternator develops an internal short through which the battery tries to discharge. This happens more than you might think. Shorted/ damaged diodes, shorted stator, etc.

On the other hand, it becomes damn difficult to actually protect anything 60A / larger without what can be expensive devices. Fuse links are the simplest, except "they ain't that simple." I don't know of any reliable chart that says "you take X length of part no. Y fuse link," etc. You could do your own experiment there I guess. This would require some amount of links you can replace in the main charge line, and a variable load (carbon pile.) I'm afraid most of us "just gamble." You obviously need something which will carry the max alternator rated output, but will blow without burning anything down. At the 100A level, this becomes somewhat more difficult.
 
Doosterfy said:
Let's see, where to start...The reason for going to a one wire setup is to simplify things under the hood. I've used one wire alts on GM cars before and they worked good. The only drawback was that one has to rev the motor up to and RPM that turns on theialt, I.E. if you only start it at idle and leave it idling it will not charge. The last one I had I had to rev it to 3000 to get it going then after that it was charging at all RPMs. That is a non issue for me. The car is set up with a mechanical fuel pump, twin electric fans, MSD distributor, coil and 6AL box. No stereo or any other gadgets. I'm eliminating the factory bulkhead plug on the firewall and going with new 16g wires soldered and heat shrink wrwrapped at the splices. I'm making my own harness under the hood and the new harness will be spliced into the factory harness for lights, turn signals, etc. All wired going to the MSD, alt, starter relay will be new wires. The wires going to the tail light will be the original ones. I'm just trying to find out if there are items that will burn up and possibly cause a fire.
Click to expand...

Can't you run direct battery power to the alternator through a relay that is triggered on by the ignition switch? We just wired a Jeep Willys in the shop the other day. The PO put in a one wire GM alternator that didn't charge until high rpms. My tech drove one of those Jeeps for years in the service and did exactly that. It charged at all rpms after that. I'd have to get more info from him, but I believe that is how he wired it.
 
One six inch wire going from the alt. to the battery terminal bulkhead. I still use the original battery cable going to the starter and the wire going to the relay I just have a bulk head as my pos. terminal with a cable coming from the trunk. besides the fan and pump relay wires coming out of this bulk head there is 4 other wires
black is altenator
small red is relay
medium red is starter
large red is pos. battery cable from switch in the trunk. which is operated with a pull handle in the back up light

Kill switch in the trunk also cuts power to the MSD.
 

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famous bob said:
no one mentioned that it would be getting rid of the stupid voltage reg. on the firewall. I`m going to run a 75 or 80 amp 1 wire, of course I`ve installed a new wiring system, only stock stuff left are the pigtails to switches - lights -etc., all new gauges, tail ight sockets etc. msd ign.
went w/ E Z wiring kit. any problems w/ their kit and u can call Sean for advice.
he is one smart sonofagun!----bob
Click to expand...

Same, works great!
 
I'm probly going to go with the 60 for safety. The battery is in the trunk and I have a disconnect switch. 67Dart273 and 70aarcuda, I can see both of your points. The last one wire setup I dealt with either came with instructions that said to run the wire to the battery or the hot side of the cutoff switch so that when the disconnect got shut off, the alt would not keep the ignition on. I raced it at Lebbanon Valley and the tech inspector had me start the engine and he hit the disconnect and the engine shut off. At that time this met the rules and I never had a problem with the setup. What Dart273 is saying is we're lucky we never had a short or some condition with uncontrolled current flowing and causing a catastrophy. I'll check out the NHRA rules and see. One solution I thought of for simplicity would be to add another disconnect and set it up to work in conjunction with the battery dis and use the additional switch for the charging wire.
 
I ordred a 75 amp unit. I did not see the 60 amp one listed at Summit. I contacted Powermaster Tech and they said run the wire to the hot pole on the disconnect in the trunk. They also said to run 6g if under 10ft and 4g if over 10 ft. I'm starting to agree with 67Dart273. I'm not too crazy about running another big wire the length of the car and not have some kind of safety device in the circuit. 67Dart273, you had talked about a relay setup before. I have looked and see lots of 12 volt relays in the 75 to 100 amp range. Most cost around $25 to $35. Is it possible to use a relay in the engine compartment that would enable me to not have to run anothr big wire to the rear of the car? It would be great if the alt output could be fed to the hot post on the starter relay and rely on the already large battery cable to bring the charging to the battery. If possible a schematic would help. Remember when the disconnect gets switched to the off postion the ingnition and engine must shut off.
 
You don't need "another big wire" to the rear if you use a double pole (4 terminal) switch. Just run a pair of no 14's up front.

If you are running MSD, which powers up/ down with a low current "enabling" wire (the small red) all you need is to:

Feed your ignition switch, through a fuse (say 5A) to one of the no 14's going back. Where the other comes back up, run that to your MSD "small red."

If you are running an ignition other than MSD, which requires more switched current, just take the no 14 coming back up front and use it to "key" a Bosch style relay and use that to switch your ignition.
 
Hey everyone, I just want to let you know how I made out. I got the car running. As I stated, I went with a Powermaster 75 amp one wire unit. It came with a card that said it makes 96 amps @ highway speeds and 67 amps @ idle so it's actually a little more than 75. I by passed the factory amp meter and installed a volt meter. I also went with the four pole battery disconnect and ran the MSD trigger wire back to it per the advice I got. I was not able to drive the car more than up and down the street a couple of times because the trans has a serious issue but so far the electrical system has been working perfectly. The running voltage on the gauge is always 14 volts and the head lights and all the electrical items on the car work very good. I completely ditched the factory harness under the hood and made a complete new one that I routed around the perimeter of the engine bay. I added two new fuse blocks, one under the hood and one under the dash and also still have the original one in use. I also got rid of the factory wiring bulkhead plug on the firewall and did a hard wire setup with all soldered and heat shrink wrap and I labelled every wire and put clear heat shrink over the labels. Everyones input was very helpful, thanks to all. I'll keep you posted next year when I start putting some miles on it.
 
Here's an update. I drove the car all summer. I drove it back and forth to Lebanon Valley Dragway twice (100 miles each way) and ran mid 11s with a best of 11.48@116. The only problem I had with the electrical system was the two plastic body 30 amp fuses for the cooling fans started melting the plastic. I replaced those with 30 amp breakers from Jegs and had no other issues at all. All in all the one wire alternator works very good, I would do the electrical exactly the same if I were to do it again. Also want to say, thanks a lot for the advice on the wiring with the four pole battery disconnect. That was very good advice and my car is safer because of it.
 
Very good. Now put that thing away for the winter, LOL
 
67Dart273 said:
Very good. Now put that thing away for the winter, LOL
Click to expand...

Lol, I did just that last week. I have a buddy with a nice collection of Mopars in a nice new steel building. My car is tucked in the corner under a 71 Satellite Sebring 383. It's in good hands with good company.
 
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