As some of you might remember after breaking a few parts on my old FB at an autocross i decided to built a Turbo FC just for racing events. After I bought the FC i went to the guys house 5 hours away to find out it barely ran. After about 3 hours of tinkering with it i found a way to make it limp the 5 hour drive home for the tear down. The engine was rebuilt but basicly all the wiring in the car was chewed by mice as it sat in storage so i cut every wire out of the car and started from scratch.



At this point i have all the wires from the stand alone ecu in and the engine is running strong, I have rewired all the lights and they are working well....BUTTTTT......................



How do i wire in the altonator to make it work. there is one stud sticking out from the back pointing to the drivers fender, i'm guessing that goes directly to the battery?? Than there is a plug on the back side with two wires in it.... what do they do? Any help would be nice, the FSM dont tell me **** and i dont have one of the haynes books.

that plugs into the harness coming out of the driver's side.



kevin.

I was always wondering that cause i don't have the plug on my harness so its never been pluged up. What dose it do anyways

the plug to the alternator? i dunno probably does the voltmeter, turns off the battery light and some other stuff.



kevin.

Guess you didnt read my post, I cut all the factory wires out, i'm asking this question so i can wire it correctly to my new wire system.

well i gave you a lead, aka check the driver's side wiring harness diagrams and youll have to find it somewhere there.



why would you cut the driver's harness? i guess if im bored ill waste my time looking through diagrams for you, nevermind the fact you havent even mentioned a year or model.



kevin.

yea, at the very least we need to know S4 or S5, because the alternator types and wiring was different between series. If you search for FD alternator you will come up with a few pictures on how to wire S4, S5, and S6 alternators into an FC.



The actual plug on an S4 went into the engine harness (on drivers side of engine bay), and is a charging signal (for the ECU, batt indicator light, stuff like that) and + voltage IIRC, and the post i believe is ground, altho look these up for yourself, since its been a while since i dealt with this system on my car.

Get with me on Aim, when I get home, Ive got some pics that will make it easier for you.

the post is hot, not ground, sparks if you hit it with a wrench while turning a bolt.



ask me how i know.

I have a 86 turboII, everyone keeps talking about a wire harness on the drivers side, i have 7 wires comming through there, big one for my starter, small one for my starter, and 5 for my coil packs. Thats it, i havnt wired up my lights yet. This isnt rocket sciance guys. do i even need to use the two small wires scince i'm runing a stand alone ecu.

do you have the fuse box in front of the drivers side strut tower? I was wrong about the post, that should go to + as Lee pointed out. Is it still the S4 alternator (kinda dinky looking mitsubishi alt)?

no fuse boxes in my car at all accept the one i put in. Yes, it has the mitsu tri-diamond logo on it.



I'm thinking the large stud goes to the battery and leave the other two alone, not connecting them at all. I know it has a built in regulator but i'm not sure how it works.

why not just connect it? is there really a problem running those two wires? one is a positive and one is a negative. im so not wasting my time ripping through the FSM to tell you what they do....just look it up yourself, its only TWO wires, hell im doing two full harnesses for different cars at the same time.



kevin.

Why are you so angry all the time? If you are building these harnesses I'm sure you must know something without looking at a book about the altonators... Just saying a simple I have no idea or this is how you do it would do... but you my man, act like I owe you $5. I didnt do anything to you.



Anyhow after reading up a bit i learned that the two wires are usefull. One goes to the chassis ground and the other goes to the ignition switch. The altonator has a built in voltage regulator. If you dont use these wires the regulator never gets turned on causing the altonator not to charge.