alternator, 3 wire to 1 wire

Pete30

Petty Officer 3rd Class
Joined
Apr 6, 2003
Messages
80
I have an 87 omc cobra w/3.0 L GM. I am replacing the alternator. the old one was a 3 wire the new one is a 1 wire. What do I do with the other two wires, can I just cap them off, or do they need to go somewhere? Thanks!
 

petryshyn

Commander
Joined
Oct 3, 2001
Messages
2,851
Re: alternator, 3 wire to 1 wire

You can tape them off separately, but if you had a charge indicator light before, you will lose it with a one wire alt. Its too bad you went to a one wire alternator. A three wire is superior... :(
 

Pete30

Petty Officer 3rd Class
Joined
Apr 6, 2003
Messages
80
Re: alternator, 3 wire to 1 wire

Thats not what I wanted to hear, :( The charging light aside, what are the benefits of the 3 wire?
 

petryshyn

Commander
Joined
Oct 3, 2001
Messages
2,851
Re: alternator, 3 wire to 1 wire

A 3 wire senses regulator voltage at the battery terminal which compensates for any charge lead loss.<br />A one wire alternator senses regulated voltage at the output stud. What you get at the battery is always less than the regulator setting, especially at high charging rates.<br /><br />A 3 wire has a low "cut-in" rpm which in some 1 wire units requires the engine to be reved before charging starts.<br /><br />And of course, you lose the indicator light.....<br /><br />The only benefit to a 1 wire is that its easy to wire in, and an ignition switch is not required.... :( <br />If you go to the one wire alternator, be sure the charge lead is big enough and you won't have any problems....
 

C17LoadSmasher

Petty Officer 2nd Class
Joined
Nov 24, 2001
Messages
152
Re: alternator, 3 wire to 1 wire

The man knows his stuff! When it comes to anything electric...Schematic is certainly one to listen to! :)
 
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