New alternator install, help needed
#1
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New alternator install, help needed
Hey all, I bought a powermaster alternator with 140amps because my old alternator died. Figured I needed an upgrade because I'm installing a new fan setup in the future. It is a one wire setup but when I hooked her up....barely any volts. I'm not sure what the problem could be. Any help is greatly appreciated 🙏 thanks all.
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Re: New alternator install, help needed
I'm not sure what the problem could be.
It is a one wire setup
Return it and get one with the correct hookup for your car. Should have yerbasic 10SI wiring. Probably the most common in the world, certainly in the US.
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#3
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Re: New alternator install, help needed
Can you explain why a one wire setup is bad? I dont quite understand. My stock alternator had a one wire setup so would I have to change my entire wiring setup to the battery?
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Re: New alternator install, help needed
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Re: New alternator install, help needed
My stock alternator had a one wire setup
Your stock alternator had 3 wires.
Can you explain why a one wire setup is bad?
Your stock alt had 3 wires: one Big Red one that carries the charging current to the batt; a brown one that went toward the ignition switch via some resistance (often a warning light), such that it was fed ign voltage through the resistance when the key is in Run (but not in Acc, Lock, or Off); and a 3rd wire, which varies from car to car as to its color and destination, butt, which carries the voltage signal to the alt that it's then supposed to regulate.
The "exciter" or "field" wire tells the alt that the ign is on, and feeds a small amount of current into the field winding, which allows the alt to "start". The alt is essentially self-exciting once it "starts", but without that "starting" current, it might never do anything at all. In fact it won't even know that it's SUPPOSED TO be charging, because it won't know that the ign is even On. One-wire alts make this connection internally somehow. It's usually not as effective as the wiring that comes in cars, butt for the situations that a 1-wire alt is for, such as race cars with no running load other than a distributor, or pumps, generators, tractors, etc., it's usually adequate.
The 3rd one is the "sense" wire. This is the alt's "eyes" on the electrical system. The alt generates whatever power is necessary to ATTEMPT to keep the voltage AT THAT POINT, wherever that wire is hooked to, at the constant regulated voltage (14.2 volts or so). A 1-wire alt connects it directly to the alt output terminal. This works FINE for a very small electrical system with no significant load other than charging the batt, such as things mentioned above. Butt for A STREET CAR, with lots of OTHER loads like ... electric fans, headlights, blower motors, stereos, fuel pumps, AC, etc. ... and LOTS of wire, connections, switches, relays, etc. between the batt and the loads, there can be SUBSTANTIAL voltage drop by the time power reaches the loads. Like, the alt might be working PERFECT, butt in the 1-wire configuration, there'll be 14.2V at the Big Red Terminal on the alt; then a tenth less here, acoupla tenths less there as the current flows through all that other stuff to get to the loads, that there'll be FAR less than that at the loads, WHERE IT MATTERS. To compensate for this, the "sense" wire needs to be hooked up well downstream of the batt, so that the alt can keep the voltage AT THAT POINT constant. The best place to hook it to in most cars is the Ignition bus; downstream of abuncha Big Red Wires, some splices, C100, the ign sw, and some Big Pink Wires. All of which create voltage drop under normal electrical loads.
So, what you need to do now is, get THE RIGHT alt which will NOT be a 1-wire, FIND the connector with the other 2 wires in it, that your car was originally equipped with; and plug it back in where it belongs. The plug you are looking for will look alot like this https://shop.advanceautoparts.com/p/...5841/5472830-p except of course that the one terminal probably won't be twisted sideways like the one in the pic; and the wire that's white on this replacement one, will be brown. The other wire will probably be red butt may be some other color, I don't know for sure in your car. It might be possible to de-1-wire-ify your inherently 3-wire alt and return it to the stock wiring, if it simply has a thing plugged into where the connector goes; and then plug the connector in your car back into that spot. Powermaster might be able and (more importantly) willing to tell you that, I don't know.
Last edited by sofakingdom; 07-23-2024 at 01:29 PM.
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Re: New alternator install, help needed
'85 and '86 IROC TPI normally came with 97 or 108 amp 17SI alternator-you can install CS 144 as upgrade(same mounting and almost same design as 17SI,but more modern regulator for better low-rpm output) Several different 1986.5 to 2001 GM cars used the cs144 alternator including LT1 4G f-bodies.
#7
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Re: New alternator install, help needed
I have an 82 TA w a powermaster 140 1 wire alternator. It works great. No issues with it at all. That said, nothing is stock in my car. There's a power distribution block powering the EFI/spal fans/fuel/etc. I think the points sofa makes are good and totally legit. I'm sure you can get the alternator to work and maybe even work well. But you're gonna need to figure out the issues or swap it out. It powers all my stuff well, the only down side I have with it is my belt needs to be really tight otherwise it squeals at startup and really fast off idle acceleration. But it's a v belt.
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#8
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Re: New alternator install, help needed
[QUOTE=Firechicken82;6538977. It powers all my stuff well, the only down side I have with it is my belt needs to be really tight otherwise it squeals at startup and really fast off idle acceleration. But it's a v belt.[/QUOTE]
yeah, im having the same problem with the squealing too. Any tips on tightentightening the belt?
yeah, im having the same problem with the squealing too. Any tips on tightentightening the belt?
#9
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Re: New alternator install, help needed
I used a large bar to get the leverage to move the alternator. It's good once it's really tight. I'll have a better fix this winter when I swap the serpentine drive w a centrifugal blower.
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