Weird tapping sound only when lights are off

[killajamal]

So I just noticed a weird tapping sound in my motor when I turned off my lights. It also goes away when cooling fans start up.
Its a 93 L. It doesn't make sense to me.

[Legacy777]

See if you can try and narrow down where the noise is coming from. The only thing I can think of that would be affected by the lights turning off and on would be the alternator, but again see if you can try and narrow down where the noise is coming from.

If you think the noise is coming from the alternator, try removing the belt and spin it by hand to see if it spins freely or not.

[killajamal]

I grabbed a stethoscope an it sounds like its coming from the center of the block. Alternator was my first guess. But I guess I'll just see what happens. Hopefully it doesn't blow up!

[turbo970]

lifter tic? mine did that noise too sounded like it was from the block but was from the lifters. did some research and put sum MMO in and it worked its quieter now other that the normal subie engine noise