What exactly does that do?

 

I ran 10 gauge wire, seemed to work fine. It helps boost the battery by running from the + terminal to the output post of the battery. During idle this helps alot for some people to keep the volts up.

 

I thought that the wire already ran direct to the battery...

 

Well yes, you could aternatively do It that way. I suggested the way that would keep It In stock appearance.

 

i have all 3 alts, 70 amp for the S4, 80 S5 and 90 FD... also the fd has the same conector as the S5 so it the hardest thing would be the shaft... which im doing what one of the other rotorheads mentioned put a dual on and wire in the conector to the harness, not to bad... also you could go to a Alternator repair shop and have them do it pretty cheap as for getting the pully on the shaft.

 

What I am trying to figure out, is what EXACTLY does this do?

 

Well, it DEFINATELY WORKS! I got a jump from 12.4 to 13.7 V.

That rocks!

 

I just got done putting the FD alternator in my 88 and it was a breeze. I rather just run the 2 jumper wires from that harness that way if you want to go back for some reason or have to, to your stock alternator you dont have to cut the harness YET again. You can't really even see the wires because they're behind the alternator except for maybe an inch that comes out to plug in the side. I think it looks good. Simple install except for having the pulley drilled out but that took 5 minutes. PM me if you have questions

 

The FD is 100 amps, not 90.

 

I am still not getting enough AMPS from the stock alternator, so I am going to the FD alternator this week.

Rat

 

The best way to attack this is to save up a couple hundred and a weekend to revamp your entire charging system. I had these same problems on my 87 t2, and with an e-fan and stereo(and foglights) it just wanst going to work.

I got a nice s5 alternator adn installed it. It is nice if you have the clip to go with it, but you can do as described above and use 2 female speaker terminals to connect the wires to the alternator. IF you look in the FSM and on the back of the alternators, you can see S and L, just match those leads back up. You can use an na alt. on a t2 adn vice versa, just loosen and rotate the battery post on teh back of the alt.

Before, even without the e-fan, I would see a max of 13vdc at idle, usually closer to 12.5. I bought a new battery, a 925CA battery from walmart, the biggest baddest one they sell, was only 59 bucks with a 7 year prorated warranty. I bought 2 new posts, and 25 feet of 4 gauge stereo power wire, alogn with appropriate connectors. I did this because I was relocating my battery to the hatch at teh same time, so you wont need more than a few feet for a stock application.

I ran new wire from:
-my battery ground to the chassis using a bolt, a large washer, and ground down to the sheetmetal.
-my batter + to the starter terminal, clean the starter connection when doing so
-my alternator + post to the starter + terminal
-the fusebox main power supply (underhood 80A fuse) to the starter + terminal
-the starter frame(engine) to the chassis, cleaning and grinding both surfaces down to bare metal.

Then I ditched all teh stock wiring left over. You have now rewired your entire main charging circuit. Simple isnt it?

IF youre keeping stock battery location, do the above with new battery cables and terminals. Keep the connections clean. Replace every wire and connector(total cost less than $50) and you'll get a LOT of power in return.

So, what do I see now?

daytime cruise 15vdc on the highway, 14.5 at idle, 14+ at night with all the lights on. BIG difference. Helps a lot with starting/flooding issues on the engine too, when the starter can actually kick the engine over pretty hard, it starts on teh first rotation.
I give it a 10, and it should be one of the first things done to an old car that youre going to keep/modify.

 

hypnotyz7