[Mightymouse]

On a 305 sbc theres a wire that screws into the back of the alternator and one that plugs in.. with the one that plugs in theres a red wire and a black wire where does the black wire go?? my guess is it is a ground? the car is a 85 monte carlo.

 

[Novaman78]

yes the black one is a ground. I grounded mine to same place as battery. The other 2 wires are hot wires.

 

[Mightymouse]

yea thought so.. Thanks

 

[Novaman78]

No problem. Somebody help me out on this cant you make a 2 wire alternator into a 1 wire alternator by running the 2 red wires into 1 wire?

 

[poncho62]

Are you sure that the wire isn't brown?

If it is, it goes to an ignition source to kick start the regulator, which makes the alternator charge.

 

[Mightymouse]

Well see.. last night i got to messing around with stuff on the engine and i somehow disconnected that wire from something and forgot where it went the next day but it went somewhere back by the distributer and i cant figure out where

But there is a good possibility it could be brown...

 

[coldknock]

The red wire is for voltage sensing and the brown wire is the field wire. You need to have the small red wire connected to the circuit feeding the interior. Make the connection about halfway to the bulkhead in the firewall that supplies power to the fuse panel

The small red wire is used by the regulator to measure voltage drop. If you connect it right to the + output, the alternator won't properly charge the battery. It will see the output of the alternator with no length of wire to cause a drop in charge voltage. This is especially critical if you have an electric fan, big stereo amps or anything that will drain the battery quicker than usual.

The brown wire is just for the idiot light in the dash. It will provide a ground and make the light come on if the regulator flops.

Larry