Bad Voltage Regulator??

Started my truck this morning to go to work, battery light came on instantly. Drove a bit and the light went off, soon after my fan speed started going up and down like crazy. I checked the voltage on my scangauge gauge and it was varying between 13.5 - 17.1V!! The battery light never came back on, but there is definitely something wrong.

I'm assuming its the voltage regulator, but I think the regulator is inside the alternator, so probably best to change the whole thing. Truck has 135,000 miles, so its probably due anyways.

Thoughts?

 

Sounds like a voltage regulator to me. Be careful not to cook your battery. You could always find a parts store to test your alternator. I had this happen to an old dodge but didn’t notice till my battery had swelled up like a balloon and was leaking acid down my engine bay

 

It is most definitely the voltage regulator in its way out. You can either change that or opt for the entire alternator replacement. Like @Greenedmc said, repair it quickly!

 

204k mi on my 05 OEM 130amp alt

 

And absolutely DO NOT buy a rebuilt alternator from Autozone, Orielly, etc. I don't know what sources you have up in Canada, but many TW members have had good results with Denso alternators.