i need help wiring my alternator up. i have a chiltons but i am not good with rewiring. i dont know if the guy before me wired it up right. i am in the process of putting in a motor so would like to fix wiring first. my connector coming out of alt has a red wire that is short and looks like it goes to the bat conn on the back and a black wire that goes into the harness,also it says there should be a orange wire also but how does the alt get power from the bat do i need a cable to go from the back to the starter or to the bat any help is nice

 

What engine do you have in it, I have the schematics for the 85 firebird that might help you.

 

I HAVE THE 5.0 I DO HAVE THE WIRING LIKE YOU PUT UP ON A NOTHER POST. I HAVE AN ORANGE WIRE THAT HAS A LOOP END ON IT THAT COMES FROM THE PASS SIDE THAT LOOKS LIKE IT WOULD HOOK TO THE BACK OF THE ALT. ALSO HAVE THE PIG TAIL CON A BLACK WIRE COMES OUT GOES TO THE DRIVER SIDE ALSO HAS A RED WIRE THAT IS SHORT THAT LOOKS LIKE IT GOES TO BACK OF ALT. I WAS TOLD I NEED A LEAD TO GO TO THE STARTER BUT THE SCHEMATIC SHOWS A LEAD TO THE BATTERY IS THIS THE SAME

 

the problem is that they are all the same size and are all the same red,

one of them is your solenoid cranking engine wire, so you need to test for that one with test light and hold key switch allw ay in cranking position and locate it and label it and then ignore it in future til all this wire figuring out is done,

next you need to find one of the bigger ones that had the small diameter metal flat round ring crimped on the end of it for the alternator BATT charging post

rest of them all go to battery source, a small one and a bigger one paired together for the positive batt post on the starter solenoid,

and one last one went to spade connector on the side edge of the alt case, upper when alt is installed,

you can run that alt spade wire from the spade on the alt over to the charge BATT post on the alt if you get confused, just use the 4 or so inches od wire to run it from the spade to the backside of the alt to the post,.


if you want i can try and distinguish different sizes and tints of coloring to the red wires to these on my 82 t/a 5.0L car, its all factory original no cut wires, at all,

the wires that want to lay across intake or on valve cover are your alt wires, you will have total of three wires to there, a small brown one, and a big red and another big red,


starter positive cable post on solenoid takes one small red and a big red,

then S terminal on solenoid takes big purple wire, but it can possibly be red, but make sure is no purple one first, no actually make double-triple sure, if no purple down over there anywhere out of the big harness alkong tranny bellhousing then pick the wire that lights up hot with key switch all the way in crank position

that wire along with the rest of the starter wires all route through a stamped rolled metal tube thing thats about 4 or 5" long at rear of engine and protects it from melting from exh manifold heat, it should have one or two bolt hole rings part of it, it sits sideways along whre oil filter base/adapter would be if there was one on that side of the block, held in place by low bewllhousing bolt down there, easy acces to starter and solenoid and this metal tube when the exh manifold is removed, very easy access !




good luck