Putting an alternator in my son's '60 SBC powered chevy pickup. Basically rewiring as we go as the old wiring is missing or shot. Ran a wire from ignition switch to the alt. that is 12v when on/0 when off. Don't have the alt. feed wire hooked up yet only the the wire that loops back to the output stud. When I turn the key on (engine not running) smoke starts to wisp out of the back of the alternator. The case, wire to the alt. and the plug are all cold to the touch. This is an old alt. taken off the shelf, no nothing about it... Is it possible that there is just dust, lint, etc. that is heating up on the diode trios and burning off? Is this an indication that the diode trios themselves are bad of perhaps some other internal malfunction? Thanks-
Delco 10SI? The voltage reference wire should be on Terminal #2. Chances are the alternator has terminal cancer if it has smoked for any length of time.
Um...oops, I had it going to the #1! Was using an aftermarket plug and harness and thought that was the way it was supposed to go. No worries though I will swap in another alt. and change the harness and try it again... thanks!
It is a 10SI - I may have had it correct the first time I think after doing some more research - everything I find says to run switched 12V off the ignition switch to the #1 terminal and the #2 to the alt. output?? Maybe I had it correct and the smoke was an internal alt. problem??
I've saved several diagrams for hooking up Delco 10 or 12SI alternators here https://s173.photobucket.com/user/mr48chev/library?page=1 You do have an internal regulator alternator with the pins going _ _ and not an external regulator alternator with the pins going l l ??
Terminal #1 is for the charge indicator/idiot light. Running 12 volts to this directly from the switch would probably make smoke. There should either be an idiot light or resistor in series between the ignition switch and terminal 1. Terminal 2 is the voltage sense lead, and should be run as close to the + battery terminal as possible in order to let the regulator in the alternator know what the voltage is at the battery. This wire does not need to go through a switch, and can be connected at all times.
This is the magic smoke theory. It is possible to buy replacement smoke, but you have to make damn sure to get negative earth smoke. If you use positive earth smoke, your stuff will work backwards. If you get replacement smoke, make sure to get a smoke replacement tool or your smoke might leak out before it makes it into the wiring harness. https://images.app.goo.gl/M6XMWzBTJhdJnJ2J6 Sent from my iPhone using The H.A.M.B. mobile app
You also need to make sure that you get the smoke sealer. The smoke replacement tool usually leaves a small hole that most definitely needs to be sealed, or your smoke replacement efforts will be in vain.
Thanks for the info. Ebbsspeed. If I understand correctly, 12V switched on, through a light wired in series, and then to the #1 post? The light in the circuit will provide enough resistance??
Yes, the light will illuminate when the switch is turned on, and once the alternator is producing current the light will go off.
Ok I think I am getting this figured out... I have the #2 wire looped back to the output stud on the alternator...I still need a wire from the output stud to the battery, correct? Does this wire need a fusible link?? Thanks-
It will work looped back, but as Ebbspeed stated it's better to run to Battery post, or terminal block closer to battery.
Ideally: Terminal 1 through idiot light or resistor to switched 12 volts. Terminal 2 is a battery voltage sense lead and can be connected anywhere, including looped right back to the output post on the alternator. It is best to connect it as close to the battery as possible. This does not need to be switched. Output post/terminal through ammeter, or if no ammeter then to the battery via a heavy wire. Some are connected to the battery cable at the starter solenoid.
For best performance the load sensing wire should go to where most of the electrical loads connect. Such as the headlight switch, ignition switch, or the ammeter. It will keep the output at the set voltage where it is being used, instead of at the battery if looped to the output stud.