i have been told that this is a quick and easy bolt on upgrade. they also say that the S4 T2 alternator shares the same connections where the S5 connections are different. my question is, how can you tell if its a S4 T2 alternator? can someone tell me what i need to look for? are there any serial numbers that i need to pay attention to? thanks in advance...

hoang

 

Any S4, (86-88), alt is a direct bolt on and go.

 

Ok, now I'm worried, I bought this alt. off ebay. Supposed to be a "bolt on and go" 80 amp from a gen 2. The plug is different than my 84, which is ok. But I've got 300.00 + invested in a belt drive system and don't want a sloppy shim job to make it work. I've already used a brass brush on it and painted and mounted my pulley. Is this alt a direct fit? Sorry if this seems stupid, but it was one of my first purchases, and I am going to begin assembly Mon. I thought I did my homework, but you all know better than I.

 

The alt will bolt right on the mount with no problems. You have to wire it diferently, (there is a thread for the proper way on the archive).

 

If the plug is different then it's most likely an S5-S6 alt. All S1-S4 alts interchange and have the same tee plug and stud with an 6-8 mm nut. What I have found is when installing an S4 alt on a 1st gen is the shim usually needs to be thinned a hair. 80 amp alts are 'supposed' to be from the TIIs, the rest got 70 amp alts. The TII did have an additional front mount electric cooling fan that covered the passenger side of the radiator. I think it was triggered by the AC circuit.

If your alt is an S5, it will work but needs to be wired differently. Check the archives for a write up.

 

I made this up quickly...

Your alt there looks like a FD alt

 

Ok, googled the rx7 alts. and found mine. It's off of a 91 turbo. I'm sorry, but i don't have the alphabet soup memorized yet, so I'm not sure if that makes it an S4, S5 or what. ........ I'll exercise the search button and find out.

Thanks for the quick write up Sgt.Fox.

 

I am fairly certain that the connector being on the side instead of the back is a trait of 3rd gen alternators.

 

you may be correct about that.I'm having a hard time getting a definative answer. The pulley on the fron of the alt was a v-pulley when I got it. the pulley on it now is from the Gilmer drive i'm trying to install. I did find a pic of an 91 n/a alt, and it has the plug on top like mine. Would the diagram you put up aooply for a 91? Thanks for all the help, i have to get this right the first time.

 

wait, s4 alternators are considered an upgrade on 1st gens? Those things suck

 

Diagram is using the alternator pictures from the first and third gen factory service manuals. The plug on the S5 is the same as the S6.

 

Great! much appreciated Sgt.Fox.

 

thanks everyone for posting. this has been extremely helpful. members like you make this forum awesome. i was thinking of doing a direct bolt on but now i am considering upgrading even further with a S5 or S6 instead of the S4. we'll see what happens. thanks again guys.