I have a new 3 wire 65 amp, 10SI Delco alternator that came with a kit for changing over a car from 6 volt to 12 volt. The alternator is putting out 15 +/- and is supposedly self regulated. At this rate I am going to boil over the new battery. The unit will show charging with the smaller white wire coming from the DA plug going to the post is connected or not. This alternator is not serviceable from the back as some others are. Do any of you have suggestions for alternative units that would fit the bracket? Thanks in advance.
I might question the accuracy of your volt meter before condemning the alternator. I would consider 14.5 volts normal so 15v isn't that much. Phil
I took it to Napa and they tested it also. Their machine said that the voltage set point was 15.2 and the running volts was 15.4. I don't mind if it can go that high but it seems to run that high no matter what.
The new PowerMaster I just bought come with a spec sheet and it had the ability to be able to connect an I-did-lite from the original car. It is a 100amp. My son has a clamp on DC Meter and with everything on in the car, AC fan on high. Headlights on high beam, radio it read 34 amps and 14.4 volts. Perfect to me. This reading was on the wire attached to the alternator and leading into the car. By putting the clamp on just the main positive cable the meter read 1.8 amp. To me this said with everything on the battery was still being charged. Yes the horn would have been more along with the brake/turn light but they would not have been a constant. Each stage of the fan speed dropped the amps. I’m saying this because the voltage never changed from the internal setting with nothing or everything thing on... I personally think 15vdc is too high but with your car at idle and about 1500 rpm see what a good volt meter shows connected directly to the battery. The spec sheet in the photo shows a voltage setting of 14.8 but on my volt meter connected to the battery it was 14.2-14.4.
The only thing I know of is swapping regulators. Some of the cheap rebuilder regulators can be off one way or another by a bit too much. Every 10 or 12 SI alternator I have ever seen has to have the case split to get to the regulator and diodes. I've rebuilt a lot of them over the years. I try to save every alternator hook up diagram I find on the net here Photobucket In an album on my photobucket account. One is for a 10DN with external regulator that along with the photo of the one wire unit don't count. One shows using the diode in the exciter wire, another shows how to swap from an external regulator alternator to an internal with stock wiring. That works for most 62 to 72 GM rigs. I don't have the one to go from generator to internal regulator with stock wiring.
That’s a one-wire. He has a three-wire, so connector pin 2 (not used on yours) is important. Sent from my iPad using The H.A.M.B. mobile app
Phil P >>>I might question the accuracy of your volt meter before condemning the alternator. I would consider 14.5 volts normal so 15v isn't that much.>>> Absolutely! But if Stonehenge is a fussbudget and worries about a half volt over, he could pigtail the #2 terminal directly to the alternator output and maybe worry more about a half volt under. Jack E/NJ
Or just get another one from any auto parts store. Get one for a 1973 Camaro or Corvette, you just need to look at where the plug location is (called the clock position). Then look on Google on how to wire up a 3 wire 10si. Also you might need to switch the pulley. Really great alternators and fairly cheap to buy.
If your voltmeter is reading correct and your battery is good then you soon after starting up the voltage should show between about 13.8 to 14.5 with nothing else switched on. If the battery is no good then it will run high voltage all day long trying to charge it. If it does not and if it is new and you have just fitted it I would get in touch with the supplier. If it is and old one then it sounds like the regulator is faulty.
Thanks for the info. guys. Yes the voltage at the battery shows 15 + constantly and yes the battery is new. seems to show slightly more charge at higher rpms. At rest the battery shows close to 13 (12.6 +/-). I currently have no regulator set up in the system (1940 Ford car). The kit supposedly eliminates the need for that device. The new alternator is a 3 wire and seems to charge full tilt no matter where the white from the DA is hooked or not hooked. Also moving the red wire from the DA going to the larger battery post on the alternator and going directly to the battery post seems to have no affect. It would seem that having a reading of 14.5 or a bit less would be better for the battery and system in general correct?
Trying again... exactly what do you have hooked up, where? You have a three wire alternator. That has ... wait for it ... three wires. One is the alternator output. One goes to the idiot light. One is the sense. The sense wire is an input to the alternator, telling it how much to put out. Sense is used to ramp alternator output up or down, depending on the electrical system load. It sounds like you have hooked output to the battery, and have not hooked sense up anywhere. You can ignore the idiot light if you want, but you cannot ignore sense. If you don’t want to run the sense wire, you need a “one wire” alternator. These just basically hook up sense internally so that the alternator always puts out the same voltage, regardless of electrical system load. Sent from my iPad using The H.A.M.B. mobile app
Sorry when I said about the regulator I should have made it clear the regulator is built into the alternator.
On the back of the alt it should say 1 and 2 on either side of the plug. The #2 goes to the battery lug on the rear of the alt and #1 either goes to a warning light (which I personally like) or to a diode (it needs to be in the right direction)....both of these end up going to the ignition circuit. Start it and let it run, turn on the headlights and see if the voltage goes down. You might have a bum or special internal regulator, you can go buy a regular 10si off the shelf and it will work great. Also make sure the wire from the battery to the stud on the rear of the alt is in good shape as it uses that to sense and adjust itself.
More simply put, here's how they work in laymans terms. A one wire alternator charges the battery, thats all it does, the battery runs the car, the alt just keeps the battery healthy. Three wire? For me, preferable. White wire....turns the alternator on, run this to the acc side of the ign switch, so you can shut the car off, when you turn the key on it sends power to the alt, saying, OK, we're ready to run. When the engine starts, power is sent backward through this wire to the switch, if not wired right, you'll create a loop and you won't shut the car off. Red wire.....operates the regulator, telling the alt how much to put out. I hook this wire to the feed for the fuse box, and the power draw from the fuse box tells the alternator how much power the car needs, regulating power accordingly. If you hook this wire to the power outlet on the alt, it senses battery needs and keeps the battery charged, then the battery runs the car. Heavy red wire....run this to the starter, where the battery cable is hooked up, to recharge the battery and run the car. Should be at least ten gauge, eight gauge is better. Clear as mud?
Actually the battery is really mainly for starting the car. Once it starts, the alternator takes up all the load. The alternator should be sized to meet max amperage load with about 5 amps left over to charge the battery. You can prove this with an amp clamp. With the engine at 1500-1800 rpm (to allow for max alternator output), you will find that current is flowing into the battery rather than going out.
I am with IoIdtimer on this one. If it is the regulator they are not hard to change, just look on youtube
I think this is what trollst was saying, either way you are correct Sent from my iPhone using H.A.M.B.
" Stonehenge " have you read this, look a#6might be the answer. thrhttps://www.jalopyjournal.com/forum/threads/question-about-alternaters.1146178/
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