Alt. wiring help please

[Time Warp]

My friend with the 84 Monte has been having issues with the battery staying charged on his car . What i can tell so far is , it has a wire coming off the stud on back of alternator running directly to the battery . The plug with 2 wires , is not there , i don't even see any wires in that area for the plug. The Alt that was on there , may have been set up for a one wire , iam not sure ( it tested bad anyways , there is no ext. regulator mounted anywhere i can find, it looks like a 10si with the 2 leads and the main stud on the back )

What we decided was to put back on the alt . from my 79 Malibu . Are the wires i need for the 2 wire plug on the alt. the same color coming out of the main harness on the firewall ? I noticed 4 wires cut right off that main harness .

 

[Goob]

There should be a small (16 ga.) Brown wire, and a big (10 ga.) Red wire for the plug.
The small Brown wire is the indicator lamp, the big one is the voltage sense wire, to regulate system voltage.

 

[Time Warp]

Thanks Goob ,

The red wire is off the starter correct ?

 

[Goob]

Correct, with a fusible link too, I think.

 

[grizwald]

the factory plug on my car has a small brown wire for the stock voltmeter, but the bigger red wire goes from the plug to the post on the back of the alternator, not to the starter. i had a wire running from that same post to the starter, but had to run it back to the battery in the trunk so the car would shut off with the kill switch.

 

[Goob]

but the bigger red wire goes from the plug to the post on the back of the alternator

That was usually a Buick, Olds thing, perfectly acceptable also, but does not truly sense the system voltage at the load center.

 

[Time Warp]

ok , i got the larger wire done , not positive on the small brown wire ( think i found it just want to be sure ) is there a way to test to make sure i got the correct wire to the light /gauge in the intrustment panel ?

 

[Goob]

Ground it (key on) and see if the light comes on, or use a test light, the lamp in the dash will glow through a test light.

 

[Time Warp]

Goob , thanks again for the help , i still can't fiqure out which wire it is . The car has a factory gauge in it . Whats wierd is , with only the wire on the post on the back of the alt. the gauge in dash still moves when i turn the key to the on postion . ( i thought it had to be hooked up to the plug on the alt. Guess its time to just get a one wire alt.

edited below here ..
i found this site here http://www.oldengine.org/unfaq/10si.htm . i thought hooking the number 2 part of the plug to the battery directly would drain the battery over a few days , is that not the case ? is there an actual warning light on a 1984 monte ss ?