Bought a new Tuff Stuff alternator, this is the 175 amp, not the 250. When I installed it and started the jeep, which is a 2013 with the 3.6, the volts jumped straight up to 18+, all lights on the dash came on and fan started blowing on high, even though it wasn't on. Shut her down, installed the stock alternator, and everything is fine.

Called Tuff Stuff, they told me it needed to be grounded?? So, to appease them, ran a ground from one of the bolts to the neg battery terminal,,,,,same thing, volts went to between 18 and 19 and every light come on the dash.

So,,,,I hear about people running high output alternators with no issues but I got to think it has to do with it being a higher output then stock. Any ideas on what is going on here? I sent the alternator back to them and there telling me it checks out just fine. So I assume it's the internal regulator that isn't liking the higher output, even though it's only what 15 more volts then stock.

Any input would be greatly appreciated.

Thanks

 

I am not familiar with your specific vehicle but most alternators do have the regulators included in the unit now. Having 18 volts is not good and clearly reflects it is not regulated. You made the right choice not using it since that can cause a lot of damage. These are pretty easy to install. Of course you would have to make sure connections are clean and tight (ground) including the connections for the bolts. One thing that comes to mind, are you sure what you received was the correct one for your vehicle?

 

It sounds as if this is the wrong unit possibly. I wouldn't run an alternator that isn't at least the same amperage as the stock. This isn't a terribly expensive part or difficult install. Can you return it and just get a Napa Lifetime or something that has the correct amperage?