I've got a s5 n/a rx7 and i'm upgrading to a fd alt. now my question to you is can i use my stock alt pulley from my alt if i machine it out? is the fc alt pulley narrower than the fd pulley? I have a dual belt pulley for the alt thats already machine for the fd alt but i dont plan on using both belt locations because i'm gonna keep my air pump connected because my aux ports work. can i just use one of the belt locations on the dual pulley and it work fine? any imput would be a great help. Thanks in advance,

Izzy

 

Why not run an Extra belt and be assured that Both your alternator and Water pump are gonna be Driven and no slip will occur?.(Like coolant and Electrical security!)
But you can run the 2 belt pulley with one belt of you desire.There isn't a law saying you "have to have" 2 belts on!.

 

well if i can find a long enough v-belt to run the air pump too, then i guess i'll use both notches in the pulley. i want to keep the air pump working like i said previously because i just got my 5th and 6th ports to work properly.

 

can you post up how you wired it with pictures please!!!!

 

^^^ i was told that the s5 plug and fd plug are the same, i don't have the alt in my possesion yet. its on the way tho. and if they are different then i will let you know how i do it.

 

The S5 clip is the same, but if you're talking about an S4, here's what I did.

The wire on the S4 harness that has black matches to the white/black wire on the S5 plug.

 

sorry should have specified earlier i have an s4

either way did you make that wiring harness or find one somewhere, is the rest just plug and play.

is the connector the same, or will i need to find an fd connector?

 

Attached pic will answer both S4 & S5 wiring questions.


Trying to run 2 belts on the alternator, while keeping the air pump wouldn't work well; a belt long enough would completely barely touch the water pump pulley & defeat the purpose of two belts. He's got an S5 NA, so the air pump isn't going anywhere.

 

so there isnt an "s" terminal on the connector for the s4 and i guess just wire the other terminal into the original wire "r"

 

thanks rotaryrockect88.

tyko, your s4's "r" wire will be the wire that goes to the "s" terminal on the fd alt/

 

I cut the S5 plug that goes into the alt, and found a female 2-pin connecter and wired them together the way I mentioned earlier. That way it just plugs right in on your S4. So yeah I made that adapter...

 

The R terminal on an S4 is switched 12V, while the S5 & S6 have constant 12V on the S terminal instead. Judging from BrettLinton7's setup, it looks like there's no issue with just plugging it in.