First off, I want to say I've been searching for a while (hours) and have found some info but many dead images. I am still not able to piece together the S4 to S5 alternator swap. I recall finding a detailed drawings a year ago, but cant seem to find em. It was a rough drawing on paint or equivelent of both S4 and S5 alternaotrs and what wire goes where... etc etc... Any help besides the normal reccomendations to search more would be greatly appreciated.

Thank you in advance for your help!

 

https://www.rx7club.com/attachment.p...chmentid=97289

found it!



where would the R terminal connect from the S4 wiring harness?

 

The R cable was the Ignition cable from the S4 alternator. A black/white cable if i remember correctly. Should I just leave this cable off, ie: not connect it to anything, or what?

 

It looks likes the S terminal and R terminal are the same thing, just renamed.

 

so why swap an s4 with an s5 alternator what does that do

 

Better amp output.

 

any numbers on that?

 

s4 ~60 amp
s5 ~75 amp
s6 ~90 amp

its something along those lines... the s4 one was garbage IMO. The s5 one and s6 ones are the better ones. I personally got a S6 (FD) alot and wired it up, i can post up pics later of it and you can see. I had a fused link to the battery too.

 

Im doing the same swap right now. Can I just run a small wire from the B terminal to the S terminal on the S5 alt. Then run the white/black stripe wire from S4 harness to the L terminal on S5 alt and leave other wire(ign) from the S4 harness disconnected. Thats the way it looks on the diagram but I want to be sure so I dont short anything out

 

The S terminal on the series five alternator NEEDS to go to a CONSTANT, 24HRS A DAY source of battery voltage.

IF not the battery will drain off over a day or so if you don't run the engine.

Here's a most excellent thread by that All Knowing Expert....J-RAT......https://www.rx7club.com/forum/showth...ght=ALTERNATOR

 

ok so just a small wire from the S to the B terminal would be sufficient correct because that goes straight to the pos. bat. terminal
thanks

 

this is what i have had over a year.. works just fine

 

So, do I just disconect the Ign cable completly, or should I ground it???

 

thats my next question. Where does the other wire from the S4 harness go to?

 

Why's that? because the output is lower??

 

Because it has trouble powering my headlights, defrost and my stereo. My stereo isnt anything fancy- mabey 240ish watts... I never listen to it very loudly, but that doesnt seem to matter to the alternator... It just can't cut it. Plus, my voltage regulator was dead. I hope I didn't do any damage by driving it around for as long as I have been.

 

Im not having any trouble at all with my accessories but I still dont know what to do with the black wire w/white stripe from the s4 harness.

 

The series four black/white gets tied to the harness and is not used.

 

Well- everything is installed, and wired correctly, but still have the same issue of the faulty voltage regulator... I'm getting really frusterated with this whole thing. Between bad oil seals, and the overpowering alternator- makes me want to swap the whole engine out w/ the bad alternator.