I just picked up at 2016 SL with about 90,000 miles. Car runs and drives great however I've been noticing that when I have my headlights on and the radio playing the sound will cut out and my lights will dim intermittently when taking turns. I'm wondering if anyone else has had this issue and could help save me some time with diag. I've already replaced the battery as the battery that was in the car when I bought it was a Nissan battery so it could've potentially been original. When I put my multimeter on the battery while the car is running its reading around 14v so I don't think its the alternator either. I'm not getting a check engine light or any other issues. Thanks

 

With the car running, check the voltage at the battery. Then turn on your headlights, radio, air conditioning on high etc and check the voltage again at the battery. Report back your findings. My hunch tells me it's your alternator.

 

Thanks for the quick reply! The voltage with all accessories off is 15.4 and with everything switched on it increased to 15.6

 

Perhaps others can confirm, but your voltage now appears too high. The voltage regulator is failing. It definitely shouldn't increase when applying a load (headlights, ac etc), it's supposed to decrease slightly.

 

I also didn’t think that was good. Is the voltage regulator apart of the alternator? I searched for it on Rock Auto and called my buddy who’s the parts manager at a Nissan Dealer and couldn’t find it however I found a voltage regulator connector that was identical to the alternator connector.

 

Yes, the voltage regulator is part of the alternator.

 

Thank you for your help Wizard! Much appreciated. Ordered up the new alternator and will be installing it next week. I’ll put up a post to confirm it rectified my issues.

 

Steel wool any ground connections to body as well. Use ooo wool