Romanator

iTrader: (13)

I'm upgrading my alternator from a stock 80 amp to 120amp. I took the stock alternator and brought it to a shop to get it upgraded and I have a Mazda Racing pulley installed... I have read the entire thread that jackhild59 started. I really like his post on page 9, #212 (130 Amp Alternator Sweetness)

Yes, he uses a Ford Taurus alternator... I'm aware of all the pros and cons that are explained about the rewound alternator in the other pages... He did his swap and custom bracket, I'm doing my own experimental thing.

It's been years since I relocated my battery in the trunk so I need some help refreshing my memory.

I need some clarification about the main wire... In picture 1, the loop terminal at the left that has 2 wires coming out, goes on the alternator. The other loop terminal on the right goes on the battery and that black connector is what ??? I'm guessing a ground... Is it a ground or another power wire ?

In picture 2, is my alternator. I'm using 2x 4 gauge wires with separate terminal loops since I cant find one big enough for both wires. I'm about to connect the power wire to a 150 amp fuse that's bolted on my firewall and have 0/1 gauge wire going from the fuse block to the battery in the trunk. Do I ground the other wire from the alternator ?

Also since my battery now has 12 feet of 0/1 gauge power wire. Should my battery ground wire also be 0/1 or 4 gauge ?

HOZZMANRX7

iTrader: (43)

You're already screwed with that racing pulley. When you have a stock alternator modified for higher amps, you need higher revolutions at idle of your voltage will nose dive using a stock pulley. With that pulley you're going to be challenged to get full voltage at normal driving RPM's.

Now, given your car is an S5 to answer your question none of the wires go to ground. Main terminal wire goes to the positive side of your battery, one of the two wire from the plug also goes to the battery, and the second wire is what triggers the idiot light when your alternator takes a dump. To determine exactly which of the two wires goes where, please refer to the FSM you can access online as indicated in the sticky at the top of this forum.

The wires you present in picture 1 seems to be the constant positive from the battery on one end with two wires running from it for recieving charging current from the alternator and the other the constant hot the alternator needs to see from the battery. But the constant hot plug makes no sense for a S5 alternator plug-in, but maybe does for an S4. Picture 2 shows a standard S5 two wire plug, so you have frankenstein wiring on your hands.

I recommend you punt (ProceedUnderNewTerms) and go the plug and play FD alternator route with the adaptor pulley you can get from Japan2LA Brian.

satch

iTrader: (1)

The S5 alternator has a plug on the back where one wire runs to a constant voltage source while the other wire connects to the Alternator Warning Light Relay.

misterstyx69

iTrader: (142)

The black clip that is on the wire in the first pic goes to the BIG harness by the driver's side Strut tower.It gives power to the switch.
The eyelet goes to the fuse block...The other eyelet is obviously Alternator.
now the S5 Alt Connector needs 12 volts too(one wire needs it to excite the alternator),but you can get that at the Stud on the alternator.
look at this thread Post #2.shows you the wiring to alternator. https://www.rx7club.com/2nd-generati...wiring-784580/ Never mind the title,it is the schematic that gives you the info.

HOZZMANRX7

iTrader: (43)

On second read, what Stix man said.

Romanator

iTrader: (13)

Update...

I am not screwed with that racing pulley... yet. I got the alternator rebuilt, replaced the rotor and voltage regulator. Now I get 12.6 - 13V on idle with lights on. And while I drive on the highway or city (stop and go traffic) I get 14.6V.

As I mentionned in my first post this is still experimental... So far today it's been 2 weeks. And I'm happy

First gen man

iTrader: (24)

If you are doing a full rewire, best thing to do with the L terminal is to wire a bulb in series, pulling 12v from a switched 12v source. In this diagram 1 is L and 2 is S. This diagram also includes a resistor in case the bulb blows out, your alternator will still get excite voltage.