Alternator wiring

[Larry]

I am installing an E-rod LS3 in a 33 Hot Rod. The E-rod comes with its own wiring harness. I need to know how to wire the engine harness to the chassis harness. I am using the FFR supplied wiring harness. The alternator is a GM 145 Amp.

The alternator has a stud and a 4 plug connector. The chassis has 2 connectors, one has 2 #10 red wires and the other is a 3 plug connector with a red and a brown wire. The engine harness only has 1 wire in the 4 plug connector and it is orange.

The chassis instructions state that only the 2 big red wires need to be attached to the stud and the other wires are not used. This seems odd to me.

I am also using the Autometer Volt gauge and I don't see how to connect it to the alternator.

Can any of the LS3 guys steer me in the right direction?

Thanks for any and all help that can be provided, Larry

[michael everson]

The 2 red wires from the RF harness go to the stud on the alternator. The orange wire is most likely a exciter wire. You will probably need to run a separate wire to a dash light for that.
The volt gauge can get its power from any 12 volt source. Typically the same power wire that powers all the gauges.
Mike

[Silent T]

The orange exciter wire needs to be hooked up to any 12v source from the key "ON" or even "ACC" position. It triggers the alternator to go on.
I didn't use the factory wiring for my alternator because I was not sure the gauge was sufficient for the amps over the distance to the fuse box. I used a 4 gauge wire and just ran it over to the battery feed on the starter.

[Larry]

So what should I do with other 2 smaller wires from the chassis harness(Red and Brown). Should I just cut and seal them off?

Larry

[michael everson]

That's what I would do.
Mike

[Larry]

That's what I will do.

Thanks for the help

Larry

[Larry]

One other question. The engine harness has a 10ga wire for the fan. Should I use it or should I use the chassis one. I'm thinking the engine one would be best, because it lets the computer turn the fan on or off. What do you guys think.

Larry

[rcotner]

Larry,

I am using a coyote (mustang) crate engine. Fortunately for me there is an addendum to the build manual specifically for coyote engines. With my build I used the engine fan control wire for exactly the reason you stated above. The engine has its own internal temp control system. It is best left to the computer decide when to turn on the fan.

[Silent T]

I used the LS wiring harness for the fan for that reason - it turns on the fan right around 190°.
I also had to splice in the AC system to the fan wiring. If you are running AC - it's supposed to turn on when the compressor kicks on regardless of engine temp.
I'm not at that point in my build yet but I wired it in using the trinary switch wiring diagram from Classic Air.
it may not be necessary cause I'm not sure when the AC would be on and the engine not 190°..??

[britpit]

Do you always wait until the engine warms up to turn on the AC? Or the defroster?

Wayne P.