Engine whine when lights are turned on
 

Hello fellow Yota fans!
I have a 98 4runner SR5, and have been getting a whine under the hood when I turn on my lights. I thought it was potentially the a timing belt pulley going out, and it was 10k over on replacement, but after doing the t-belt, it still makes the whine(got the kit that had the water pump, t-stat, and all the pulleys). ???? Any thoughts or ideas on what to check would be greatly appreciated.

Sounds like it could be related to your alternator. When's the last time the belt was changed?

Belts were done recently, a few months ago. I took it by my buddies shop, who did the t-belt, he thinks it might be the alternator too. We put a stethoscope on the back by the bearing..... Sounded suspect. It is the OG alt, with 135k.

alternator for sure

Check your battery negative to chassis/body connection. My clamp came loose and if I turned on the lights or heater blower there was a whine.

Is it like a shrill squeeling? if that's the case it's the alternator belt. Maybe it's a little out of spec. If it's not that high pitch then it could be the bearing.

It was a lower type of groaning. Replaced the alternator. All good now!
Thanks for all of the input guys!