SA-200 Generator/Alternator

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Hey I've been trying to get an alternator hooked up on my '69 red-face for a week or so now (was ball-parked $315 to rebuild the generator--unacceptable) but can't seem to get it to charge.  It's a Chevy alternator, one wire to the battery, then the two prongs on the side, one to excite the field and the other for?  Haven't been able to get it to do much of anything, anybody have some advice?Donk
Reply:If it's an old alternator like off of a 71 chevy, it's not internally regulated, and it won't charge in the configuration you presently have it in.  You will need an external regulator.  What I suggest, for $58, go to autozone, tell them you want an internally regulated GM one wire and be done with it.
Reply:It's a Chevy alternator, one wire to the battery, then the two prongs on the side, one to excite the field and the other for?The other side goes to the voltage gage on the dash.
Reply:Yes, that's how the system knows the alternator is charging. The other is fed from the regulator. The way you are describing your system, you will need an external regulator. Normally goes on the  frame cross member where the front motor mount hits. If your system was original and had a generator to charge the battery, the regulator for that generator was mounted on top of the generator itself. Also, that was a positive ground, I believe. Certain that the earlier ones were. If so, you will have to change to negative ground to use that alternator and add external regulator. You can avoid all this by using alternator with built in regulator.    weldersales
Reply:Are the terminals on the side of the alternator like this ll or -- ?DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:It is a Chevy internally regulated one wire, the terminals on the side are positioned --.  They are marked F and R, I assume that F is field and R is for the gauge, as you folks say (which makes sense because I've got continuity from R to the stud on the back that gets wired to the battery).  As I have it set up I am sending power to F from the signal wire on the starter.  I don't think that it has a positive ground, just because the starter is wired up like any other starter that I've seen (positive to the big stud on the solenoid).Donk
Reply:I have done this many times.  The -- Terminals ARE the regulator.  The alternator case has a hole like a D in the back.  If you put a small screwdriver in the hole and touch the terminal inside it will full field the alternator and it should put out full.To wire it, you have to put power to both terminals.  One is Field and the R is for resistor or regulator.  If you put power to one, then momentarly put power to the other, it will charge till it stops turning.If you just put power to both, it will run the battery dead.  Once it is charging, it will put power OUT of those -- terminals.  SO if you hook it to the key switch, it will feed back and you won't be able to shut the welder off.It needs a relay, or some guys use an oil pressure switch to power the regulator.  You would need a 2 wire normally open oil pressure switch.  Put power to one side of the oil pressure switch, the other wire from the oil pressure switch to one of the -- termainals.  It doesn't matter wich.  The other -- wire goes directly to the big wire on the back of the alternator.  Use 14 guage wire for all of this.Fire the machine up with the OP switch T'd with the stock oil pressure sender.  It should charge.  Shut off the engine.  There should be no draw on the battery.  If there is, switch the -- wires.  This is how an idiot light works. Switched  + on one side of the bulb, other side to one of -- wires.  Key on, engine not running, alternator draws power thrugh the bulb. Bulb lights.  Engine starts, Alternator puts + out the -- termainal.  bulb has + on both sides, Light goes out.DavidLast edited by David R; 04-24-2007 at 09:09 PM.Real world weldin.  When I grow up I want to be a tig weldor.
Reply:David R has hit the nail on the head.  If it has the dual wire pigtail coming out like he is describing then that is the regulator.  Follow what David said, and it will get ya going.  I have run into this numerous time on irrigation generators.I'm a Lover, Fighter, Wild horse Rider, and a pretty good welding man......
Reply:Hi,I'm working on my black face SA200. I took the alternator off to get tested.  I took it to an O'reilly's and they said they could not test the alternator and external regulator.  I will try a Napa since they seem to have more skilled people working there.If the alternator or regulator is bad, I think it may be just better to install a AC Delco 1 wire alternator.Can someone confirm is the 10SI alternator will work?  This is 65 amp alternator.http://cgi.ebay.com/ebaymotors/10SI-...spagenameZWD1VThanks,CharlesMillermatic Passport PlusMillermatic 200Millermatic 350P with PythonXMT 304 /w S-64 feeder and 12RCDynasty 300 DXVictor O/APremier Power Welder for my trail junk.
Reply:Ya know,,,, a Chevy alternator is a way better approach to solving your problems and a breeze to install.Just get one out of your local wreckers out of a older truck with a V groove pulley, Practically just bolts right on!Battery connection goes to the battery stud on the chevPick a wire from the top 2 terminals and wire that into the battery stud (Doesn't matter which one) with the other wire going through a 3 psi normally open oil pressure sensor. You'll have to "T" a brass block into your exsisting pressure sensor port on your engine if you have one there.That'll turn off the alternator when your not using the welder.Thats it, though you may have to use a longer belt, but all the other components will allow the new Alt to slide right in.Last edited by Cruizer; 07-29-2008 at 02:57 PM.
Reply:I agree, greasy old stock SI alternator over a "one wire" full of cheap components.They are available anywhere without paying a premium. Also the standard SI doesn't require the engine to rev up, to begin charging, and they have a truer sensing of needed charging current.Connect "2" the sense lead,  where it can get a good reading on battery voltage.Connect "1" the ignition lead, through an indicator lamp, to an oil pressure switch supplying 12v when closed.Connect "Bat" to battery, usually at the starter motor. When oil pressure comes up, the switch closes sending current to "1" through the indicator lamp, lamp goes out, and charging begins. If lamp glows, system is not charging.Good Luck
Reply:I don't much like the indicator lamp idea, nor the ignition lead, rather best to run direct to the positive lead on the starter and direct through into the oil pressure switch back to the #1 on the Alternator.Really no point running to the ignition lead as you already have a cutoff with the pressure switch,#2 you can run direct into and out of an amp meter if desired.The old "kiss" principle plays into effect here.
Reply:Originally Posted by CruizerI don't much like the indicator lamp idea, nor the ignition lead, rather best to run direct to the positive lead on the starter and direct through into the oil pressure switch back to the #1 on the Alternator.Really no point running to the ignition lead as you already have a cutoff with the pressure switch,#2 you can run direct into and out of an amp meter if desired.The old "kiss" principle plays into effect here.
Reply:Originally Posted by denrepCruizer, I'm identifying #1 as the "ignition terminal", per Delco-Remy nomenclature, -meaning it is powered when in the  "run" mode- not suggesting wiring it to the ignition switch. Yes, an oil pressure switch is a good way to feed current to #1 when in run mode.The reason for suggesting the lamp is that the OE exciter circuit is designed to have a  resister, lamp, or diode in it. Although this may be primarily to prevent a backfeed which would not allow the ignition to be shut off: IF wired to an ignition switch, as with most vehicles.Charge lamp - A nice feature, and it can be as simple as a small clearance lamp hanging in the breeze. Makes it KISS, to see at a glance that the system is charging.Sense wire - For #2 to provide accurate voltage sensing, it should be wired as directly as practical to battery positive terminal. Any added resistance on #2 can lower voltage, and falsely signal the regulator that the battery needs more charge, resulting in overcharging. An ammeter on #2 will not show charge rate, as it is only a voltage sensing lead, and not designed for system loads; they belong on "bat."Sorry I wasn't more clearGood Luck.
Reply:Could someone explain what to do with the external wires that go to the external regulator after you install a Delco 1 wire alternator?Pic of the external regulator and wire that are connected to it.Thanks,Charles Attached ImagesMillermatic Passport PlusMillermatic 200Millermatic 350P with PythonXMT 304 /w S-64 feeder and 12RCDynasty 300 DXVictor O/APremier Power Welder for my trail junk.
Reply:YA toss it, The chevy alternators have an internal regulator, thats why we the chev version....
Reply:Originally Posted by CruizerYA toss it, The chevy alternators have an internal regulator, thats why we the chev version....
Reply:Well, lets see...... just pull up a diagram and....Looks like yellow to #1 and red to the power stud on the back of the new alt. Green is not used
Reply:Originally Posted by denrep...The reason for suggesting the lamp is that the OE exciter circuit is designed to have a  resister, lamp, or diode in it. Although this may be primarily to prevent a backfeed which would not allow the ignition to be shut off: IF wired to an ignition switch, as with most vehicles....
Reply:Donk, Hope you don't mind me hitchhiking on your thread! Maybe it'll help the next guy.I needed to replace the generator -or should I say belt idler- on this old work horse SA-200:Attachment 23806Expecting the worst with the retrofit, I went to my friendly neighborhood auto electric shop and loaded up with a bunch of pulleys, spacers and brackets that had been stripped from core alternators. There was one old beat up alternator off of a Chevrolet six cylinder that had a promising but stuck bracket. After giving up on pulling the stuck bolt, the shop sent me away with the whole thing. I'm glad I followed through with the stuck bracket; unbelievably, it is an absolute perfect bolt-on bracket for the Continental:Attachment 23807The lower mounting bracket was a direct bolt on without any modification.I put just a little more bend in the original Continental top bracket.The Chevrolet lower mount made for a nice and easy retrofit. However, the pulley would need to be spaced toward the radiator.I ended up fitting the alternator with the original generator pulley and adding a spacer behind it.I wired a truck clearance light in as a charge lamp. The alternator 1 terminal is energized through the warning light when the oil pressure switch closes. Should the system quit charging the lamp lights.Attachment 23808Charge lamp function is easy to check by shorting the pressure switch, or by watching the lamp at start up or shut down; that's when the lamp lights for a second or two if oil pressure is up, but alternator is not turning fast enough to charge.Quick test shows 25 amp charge at low idle; that's plenty.The belt's too narrow - My parts chaser just couldn't get past the guy at the counter.Sorry we were cheated out of a bracket welding post! Last edited by denrep; 10-19-2010 at 11:35 PM.
Reply:Originally Posted by denrepCharge lamp function is easy to check by shorting the pressure switch, or by watching the lamp at start up or shut down; that's when the lamp lights for a second or two if oil pressure is up, but alternator is not turning fast enough to charge.Sorry we were cheated out of a bracket welding post!
Reply:Duaneb55 - Yes, more could have been done for refinements, but this was about fast and functional. The lamp ty-wrapped to the harness makes for a simple compact circuit. Although I did take the time to seal and shrink-tube all the connections, and anti-seize all threads. If I had time I'd wire in a speaker to play the Rebel Rouser if the charging system malfunctioned - and maybe Taps if oil pressure drops.The welder is going to be left unattended out on a job that will proceed a little at a time,  as time and material permits. So the rougher this welder looks the better it's odds of survival! I really don't ever remember hitting on an alternator retrofit that matched this close. I wonder if the mount could still be purchased new from GM? Also in the pile of pulleys I picked up at the rebuilder's there was a newer pulley with a heavy offset that would have worked without a spacer; it has a part number on it. I'll try to post a pic.