Baldy

I've been procrastinating on my motor swap for too long, and this is one of the reason. I have no idea how to wire the Ford alternator to the Mazda wiring.





The alternator is obviously an older design. On the back of it there is a post with a black base, post with a red base, post that says STA by it, and 2 other posts that have nothing identifiable on it. I'm not sure what wires from the stock RX-7 wiring would go where, and I'm too scared to try trial and error. I can have a pic up soon of the alt if someone really thinks it'll help.





Any ideas?

1988RedT2

This might prove to be satisfyingly confusing:



http://www.lucasee.dk/filer/engelskinfo.pdf

mazdaspeed7

https://www.nopistons.com/forums/ind...howtopic=41986

Baldy

That was all FD and GM alternator stuff from what I could see. I have a Ford 5.0 I'm trying to install, the alternator says Motorcraft on it.

Baldy

Actually that looks like the most helpful thing I've seen so far.



So just got positive to batter (or main fuse, I guess if I want to do it like Mazda had it), negative to ground, and STA to RPM meter. On that chart, for Ford it also has Field and Charging Lamp, not sure what those equate to on the Mazda.



Now on the stock Mazda alt plug (S5 vert), which wires are what? I'm guessing one is the RPM meter?





So, when the car is on and running, where does it get the power if the positive from the alt is connected to the battery? Does the power come from the battery, and the alt is just continuously charging it? I feel like I should already know these things, but I've never bothered to ask.

Baldy

Ok, looking at the wiring diagram now. There's a B/W to the main fuse, a W/L to a Joint Connector for something with the airbag, a W/B to Warning & Auto Clock, and a ground. Would I just connect all these to the positive post? And it says nothing about RPM meter...?

teknics

lol, you wont need to run your tach/RPM meter from the alternator so skip that.



the positive post on the back of the alternator will run directly to the battery (as you said, while running the alt is just constantly charging the battery)



on mazda, stock, there is a single post wire, then there is a connector with two or three seperate wires, IIRC those wires can only see specifically 12V, so hooking it directly to the alternator output post would be bad since the alternator will be giving off 14+V.



Maybe you're better off putting a GM alt on your ford motor?



kevin.

Fastenough

What year car is the alternator your trying to use out of? Ford was still using and external regulator through at least 85 maybe later. Are you using the stock serpentine belt?

Baldy

No idea. This thing is pretty much frankenstein by now. The seller said it was from an '85 Mustang, turns out it's more than likely from an LTD. The alt had no pulley on it, the main pulley was v-belt, but the water pump has the serpentine rotation (counter clockwise). I bought a serpentine pulley set and installed that.

Rob x-7

for some reason my v8 car has a mazda alternator in it.



I need it for another S5 car so im probably going to take it out and put a GM alternator in that car, and the mazda in the other.

Im also wondering if someone reverse engineered my alternator being its a mazda to work in the GM engine.