Loose belt ??

[Ramblin Fever]

Few months back, ya'll may remember, I had a new alternator put in, BOSCH. Truck runs perfect with it, no more idiot lights, dropping volts - but now I'm wondering if I have a loose belt.

All belts are new within the last year 7-10K miles or so.

Here's my issue - whenever my parking lights are turned on, I get this dull knocking sound, like the alternator making extra noise or something (if that's possible). It worsens and becomes more pronounced when using my headlights, and even louder when I use the brights.

But here's the thing, there is NO noise at all when the headlights/parking lights are off.

Anyone have a clue? Or do I just have a noisey alternator??

No other noises, problems, etc.

[mwt]

I will guess at it if you want.

If the belt was put on too tight it may have messed up the bearings on the alternator.

The extra side load when you use the lights may be mutliplying the effects
causing you to be able to hear it.

Mike