Weird grinding noise coming from engine

[87SQRBDY]

My 87 R10 Silverado is making a grinding/whining sound. Kinda like when a crappy car is backing up. It sounds like it's coming from the harmonic balance pulley, but I'm not totally sure. Any suggestions would be great.

Saw some vids about maybe it being the alternator pulley bearing. I have the v belts no tensioner pulley, 3 belts total I believe. Thanks ahead if time for your help, time and any advice e.

 

[Bextreme04]

Could be an alternator or PS bearing. Could also be a failed harmonic balancer rubbing on something. Pull the V-belt for the alternator and see if it goes away.

 

[87SQRBDY]

Thank you Bex for the tip. I'll try that one out today and let ya know what happens as well as check the power steering and balancer.