Redwood

Okay, this is pretty basic, but I just don't want to get it wrong. I'm wiring my car a little differently than stock (it's an 84 w/88 engine, see below). I have the battery in the passenger storage bin area and plenty of 2 gauge wire to use here. I'm under the impression that the positive from the battery goes directly to the starter, but than how does the rest of the system get power? I mean the lights, gauges, radio, etc.

My other thought is that there is a line coming off of the battery that goes to the system wiring (I think I saw this on my car before tearing it apart, but can't remember) and then the big wire to the starter. If this is the case, how does the starter know to take the power? I understand that when the ignition is turned to start, it cuts power to (most) everything else and only goes to one wire, but how does that wire hook up?

If you can't tell by my ramblings, I'm kinda lost on the subject. Please enlighten me here. TIA

REVHED

My best advice would be to get a Haynes manual and study the wiring diagrams.

Just quickly though... yes the large + cable runs straight from the battery to the solenoid on the starter motor. There is also another cable running to the fusible links through which the rest of the system is fed.

As for how the starter actually works... there is a wire running from the ignition switch to a terminal on the solenoid. When the key is turned the contacts in the solenoid close and power is fed to the starter motor. Pretty simple.

85RX7GS

iTrader: (1)

There's a wire that goes to the fusable link on the strut tower. That runs to a bunch of wires that go into the car.

Redwood

Perfect, thanks guys

Project84

On all negative ground systems, The negative cable goes to the starter. The cable also has a peice that branches off and grounds at the chassis. The positive cable goes all over the place, but it also goes to the fuse block in the engine compartment and the Altenator. At least that is how it was in ever car I've own in America. '80 Toyota carolla, '84 Trans Am, '87 Fiero, '82 Trans Am '84 Rx-7, '92 Mazda MX-3, '94 Ford Explorer, '96 Ford Escort, and a bunch of cars that I've worked on too.

Felix Wankel

Uh, ok. My 7 RX-7s had the negative wire going straight to ground, the positive going to the solenoid, and the fuse block/fusible link wire coming off the positive battery terminal...

Redwood

Why would I want my ground to go to the starter? Since I've only heard of a system that Felix and the other guys described, I'll stick with their ideas. Maybe American cars do that, since they're backwards in every other way. (Of course, I'm just kidding. I don't believe that all American cars are bad.)

peejay

You want the ground going to the starter (usually one of the bolts) because the starter is the highest load electrical accessory - 200-300 amps or so of juice! (At 10 volts that is 2000-3000 watts or 3-4 horsepower!) So the starter takes precedence.

Since the car is negative-ground, assuming you have a good ground from the engine to the body, every metal part of the car not isolated with rubber or plastic is negative. Again, it's most important that the starter get the closest connection to that as possible, for minimal resistance in the circuit.

Felix Wankel

Well by ground, I meant the long starter bolt, not the starter itself. I should have been more clear.

There should also be a cable coming from an engine/trans bolt or something similar to the body.

REVHED

Project84, you have this completely *** up. Why would the negative cable go to the starter? The starter body is already grounded directly to the bellhousing.

On ALL negative grounded cars the negative cable goes directly to ground and the large positive cable goes to the starter motor.

Keaponlaffen

Ground is on one of the bolts holding the tranny bell housing to the engine on my car. Positive goes to starter.

Jeff

yayarx7

I bet that bolt holds the starter on also, and that the ground cable goes to the strut tower wall first.

FJ

Not on the '84/'85 at least. The ground attaches to the engine at the bell housing just behind the oil filter mount. Close to the starter, but not at it's mounting bolt. As REVHED said, the starter grounds through the few inches of bellhousing. If the stock ground point was further away, I would run a separate ground to the starter for the reasons peejay mentioned.

The stock cable does indeed have a connector half way down the cable which attaches to the strut tower for the body ground.

More important than wether it connects to the bellhousing or starter, to me, is replacing the cables before they've corroded inside. Most people just look at the connecters.

I did add a 4 gauge wire from the battery ground to the front of the engine, at the alternator mounting bolt.
Can't have too many grounds.

Redwood: one line of your 2 gauge to the starter and another to the fusible links will be more than enough. You just have to run the alternator to the links. The original size is sufficient, as the 2 gauge takes care of the distance problem. But replacing it with something a bit smaller than your 2 gauge wouldn't hurt.

You do have #2 for your grounds also?

-John.

Keaponlaffen

Actually, mine is grounded just above the starter... the bolt that holds the metal bracket for the wiring harness... dunno if this is right, but that's where I left it when I did the engine swap. Works fine for me. Oh, and my ground doesn't go to the strut tower... just one ground to the bel housing, that's it. No problems as of yet...

Jeff