turtlevette
The Turdle
and does it work ok? How much do you have to rev the engine to get it to start charging?
who has a 1 wire alternator?
- Thread starter turtlevette
- Start date
TimAT
Addict, Cruise-In Bird-Run 1 Veteran
Ol' Red had one. I swapped the regulator back to the stock setup. It seemed to work OK, but I wanted something with no magic, so back to stock. I tossed the 1-wire thing in a drawer.
turtlevette
The Turdle
The stock replacement unit i have now doesn't start charging unitl i rev the engine a little. It seems to have a mind of it's own and doesn't charge sometimes when the engine is idling. I measured the #2 VR sense terminal at the plug and it's hot all the time as it should be. I measured the #1 switched field terminal that is supposed to be switched by the ignition and get nothing with the ignition on or off. I think i have a wiring problem so i thought i'd try the 1 wire instead of tearing into the steering column.
I went with a CS121 which is the smallest of the CS series.
I went with a CS121 which is the smallest of the CS series.
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big2bird
Charter Member, Founder Bird-Run, Cruise-In Bird-R
Is your idiot light burned out?
turtlevette
The Turdle
there is no idiot light on a 75
69427
The Artist formerly known as Turbo84
I don't have a vehicle wiring diagram handy. What's the factory mechanism to feed the alternator field current at low RPM/low alternator output conditions?
turtlevette
The Turdle
Terminal 1 which is the feed coming from the ignition switch. Later C3s have an idiot light wired in series. I guess if this connection is broken the alt can still self excite. I think this connection has been disabled on my car for a year or two. It is noticable at night as i cruise out of my neighborhood the lights will brighten as the alt finally self excites.
mrvette
Phantom of the Opera
CS or SI, they work very similar, regardles of the plug change.....
on the SI series, the red wire from the two term connector is always hot, same as the main output stud....it goes to the MOST CLOCKWISE of the two inline blade connectors, view from the REAR....the LEAST clockwise is switched.....I say this that a ways, as so many of the cases have no markings anymore...aftermarket rebuilts, whatever reason, they are not there....
so the switched hot, is the other wire only hot when in run same as ignition....
now that has a ~150? ohm reisistance wire in the absence of the dash bulb,
and so it's self exciting....I used a light duty red bulb when redoing my center dash with aftermarket gauges, had to put a resistor across the bulb as not lo enough resistance to excite that alt when cold engine, ran fine rest of the day....really marginal.....so I used a 270 ohm resistor across the bulb and it's fine, now.....
:shocking::beer:
on the SI series, the red wire from the two term connector is always hot, same as the main output stud....it goes to the MOST CLOCKWISE of the two inline blade connectors, view from the REAR....the LEAST clockwise is switched.....I say this that a ways, as so many of the cases have no markings anymore...aftermarket rebuilts, whatever reason, they are not there....
so the switched hot, is the other wire only hot when in run same as ignition....
now that has a ~150? ohm reisistance wire in the absence of the dash bulb,
and so it's self exciting....I used a light duty red bulb when redoing my center dash with aftermarket gauges, had to put a resistor across the bulb as not lo enough resistance to excite that alt when cold engine, ran fine rest of the day....really marginal.....so I used a 270 ohm resistor across the bulb and it's fine, now.....
:shocking::beer:
turtlevette
The Turdle
We'll see how the 1 wire CS unit works. It is supposed to provide 80% of output at idle. The more wiring i can eliminate the better. Anything i can do on this car to make it simpler is a good thing.
I bet the difference is that the CS has more poles in the rotor.
I bet the difference is that the CS has more poles in the rotor.
TimAT
Addict, Cruise-In Bird-Run 1 Veteran
GM made it about as simple as it gets with the 3 wire. Output, field, and excite. The 1 wire thing was invented by a bunch of guys that were too otherwise occupied to figure out how the hookup a 3 wire.
mrvette
Phantom of the Opera
RONG, the one wire was done for MARINE applications ONLY, the SI series had some special made wire screens for inside the front section and cover over the rear, the standard regulator was wired to the + output terminal and the light wire was not used.....reasoning was, back when...with SOME manufacturers, that a charge light was not needed same as with the vette, most boat engines when started go to 1500+ rpm almost immediately, the way it is with the console/gears...throttle etc....HOWEVER a boat at idle would tend to drop out of charge occationally....deemed to be not a issue....every boat I have anything to do with the electricals on, typically a old tired one....gets a new harness made up and a lightbulb to excite the alt is included.....
The CS may have more poles on the rotor/stator, never checked, thing is, the gap is smaller for greater magnetic coupling and higher outputs...problelm with the 130 was the case didn't have enough cooling, the fan simple could not draw enough air through the case.....they screwed up, and so when it's in a V8 car, like my '87 vette, there was super hot air in traffic right off the stock header...thing got too hot pulling fans, a/c blower, etc in traffic on a 100f day.....so the alt would die.....3X in 3 years for me.....
now the case is differant on the 144?5? and so it runs cooler......most of the CS alts were on FWD cars and up top in back with exhaust in front, so it barely saved the company a HUGE problem....
:shocking:
TimAT
Addict, Cruise-In Bird-Run 1 Veteran
I said: "The 1 wire thing was invented by a bunch of guys that were too otherwise occupied to figure out how the hookup a 3 wire."
I rest my case.
I rest my case.
turtlevette
The Turdle
I read through several threads on CF. I don't understand why a 1 wire alt gets such bad press. The guys using them have no complaints. My alt has been effectively in 1 wire mode for the past year or 2 and it was just the other day that i noticed slow starting that let me know there was an issue. I'm hoping the more modern alt will excite more quickly and easily with a modern electronic regulator. What Gene said about the air gap is a good point. These things are way better than what our cars came with.
mrvette
Phantom of the Opera
:drink:I figgered Tim's comment as being about CAR guys, he was including Marine/boat companies as the lazy crew....ok,......
I have been running my 17SI for some years now, not an issue, but recently repaced the center gauge cluster with a home made setup, and the light did not charge immediately upon start, the injection ran ragged at lower voltage, finallf did my resistor fix last week, and cured that problem immediately, it was a cold start morning thing, really marginal temp related....I suspect your situation was like that too, Turtle....
big2bird
Charter Member, Founder Bird-Run, Cruise-In Bird-R
mrvette
Phantom of the Opera
I guess my alt, from a '79 Seville with rear window defogger, known as a 17SI, must be something of a bastard step child...it's slightly larger diameter than the others....and factory rated 108 supposed amps....
but damn seldom if ever mentioned....
I admit I had to get 3 of them from AZ but this last one is fine, lifetime warranty....so can't complain been about 5 years now...
:smash:
00fxd
Well-known member
For about 15-20yrs I have been running 10si's as a 1 wire. I run a jumper from the far spade terminal [the internal regulator] to the output stud, no lead at all to the first terminal. That's it, never a problem. The cars will sit over the winter and not discharge. This is also possible on the 12si [metric case]. The 17si is not all that uncommon. In the day it was quite common on any luxury car with lots of power needs. We called it the 100amp. 10si's were usually rated @ a max of 80amps. I'll post a pic.
Never mind, I just went out to take the pic. That helped me to remember, I put keyed power to the first regulator teminal as well. I hope I never have to remember anything important in my old age. As you can see, it's got 2 wire's plus the 3rd is an extra ground 'cause it's a Corvette.....Time for my nap now:zzz:
Never mind, I just went out to take the pic. That helped me to remember, I put keyed power to the first regulator teminal as well. I hope I never have to remember anything important in my old age. As you can see, it's got 2 wire's plus the 3rd is an extra ground 'cause it's a Corvette.....Time for my nap now:zzz:
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mrvette
Phantom of the Opera
Yeh, I had a bad problem some years ago on the stock positioning of alt wiring, leading from the alt to the fender directly, the engine vibration managed to fatigue the wire enough that it broke and was UNDER that damn red terminal cover....so was hidden about the stress point....well it broke, and stupid ME had been running a 30 amp fuse to the computer on the then L98 injection....only because I didn't have a proper 7 amp fuse....so of course that flashing at the alt, triggered the MOV voltage protection in the computer, it blew up from all the surges, and took out the whole damn computer, INCLUDING THE CAL PAK.....I really didn't give a shit about the computer, got 6 of them, but that CAL PAK was a 200 buck killer....
:cussing::cussing::cussing: since then, it's bee rewired with one Ga. heavier wire, inboard to the intake, back to the firewall, across and out to the horn relay, the way old Goats used to be wired.....thing is, I remember looking at that factory setup when doing the initial install and thought it was bad practice, and did NOTHING about it...
Damn laziness just bites me in the ass really hard some daze....
:cussing:
:cussing::cussing::cussing: since then, it's bee rewired with one Ga. heavier wire, inboard to the intake, back to the firewall, across and out to the horn relay, the way old Goats used to be wired.....thing is, I remember looking at that factory setup when doing the initial install and thought it was bad practice, and did NOTHING about it...
Damn laziness just bites me in the ass really hard some daze....
:cussing:
turtlevette
The Turdle
well i just put my cs121 on today and it works great......so far. Need to drive another 400K miles to see how it holds up compared to the SI10.
No reving of the engine needed.
No reving of the engine needed.