More Voltage?  Do you mean more Amperage???

The problem might be that the Venge alternator is regulated by the ECM and the Stealth is regulated by an internal regulator in the alternator.  I am going to double check that, but I am pretty sure that is the case.  I will look for wiring schematics and such for you tonight since I am bored off my ass here at work.

Ok I just typed out this whole <insert naught word here> explanation and went to post it and had to log in and now its gone!  That is annoying! 

Anyway.  Yes using an internally regulated alternator on our cars will cause this code.  The reason being is because there are 2 wires coming off of each alternator.  A red one and a blue or white one (blue on Venge, blue or white on Stealth).  The red wire energizes the circuit on both cars and is the same post on both alternators.  The Blue wire on the Avenger is used to send the signal to the ECM allowing the it to regulate the voltage that the alternator is putting out.  On the Stealth the Blue/White wire is used to send a signal the voltage guage.  So, the internally regulated alternator is not allowing the computer to adjust the Voltage output of the alternator because the alternator is already adjusting it and not allowing the ECM to change anything.  Basically it is not allowing the ECM to switch the field output properly.  It shouldn't hurt anything but I would watch everything closely.  Also it shouldn't provide any driveablility problems as it won't effect air/fuel or anything like that.  As long as your car is running and charging the battery it should be good.  The only bad thing is you won't be able to clear the code unless you put the externally regulated alternator back on.

Hope this helps.
I had to print out the subcircuit wiring diagrams and do some fun tracing to figure this out.  Not to mention I decided to get my NIAT certification in charging systems so I could understand it better.  Whoopie!  Subcircuit diagrams are almost as fun as TSB's hehe.

Yeah so I just looked up the high output alternator for our cars and it is like $600 retail.  I don't blame you for using a Stealth alternator, internally regulated or not.

 

For the record though, if the regulator in the internally regulated alternator goes out, you will toast stuff and not know because you have no light.  Or you just won't charge...

Yeah, what I would recommend actually is to have the blue wire off the alternator go to your Voltmeter, not your ECM.  In theory this should work because your alternator is regulating the Voltage and you are already getting the error which is turning on your light.  That way you will have a very accurate reading on your Volt meter.  I didn't know you had a volt meter or I would have maybe suggested that before... meh!

Keep in mind if you burn something up, we never spoke