ALternator problem

[wadesbrain]

I had the stock alt seize on me last week. I figured that I would replace it and boost the power output a bit while i was doing it. I am anticipating a light rack and figured i need more output. Anyway, I replaced the factory unit (90amp) with a bosch 120amp unit and now I am getting an overvoltage reading and a check engine light. Do I need to change something else? Regulator etc. Any help would be appreciated. thanks

 

[wadesbrain]

by the way... its a 94 yj with a 4 banger.

 

[Bounty__Hunter]

The '94 should have a NipponDenso alternator and 4banger YJ may have been a 70A, you sure on the 90A?

I don't think you can change a regulator on this type of alternator.

There is a 136A NipponDenso available on many vehicles that is a direct bolt-in if you or anybody else is interested. Nearly doubles the stock output.

 

[wadesbrain]

think that will solve the problem? what a pain in the butt. ill try it out. i hate all the down time

 

[White]

I believe that also uses a exciter wire ? (Wheres NICK! ) Maybe a bootleg fix would be a resistor in-line with the field wire ? Or that might cause it to really overcharge.
Possable its a bad regulator from the start.