Loud grinding

[Omana2015]

I bought a 1995 k1500 last night ran great till this after noon I got a loud noise kinda like a grinding metal the sound is extremely close around the ac compressor the brake system light came on as well don't know if that has todo with anything I haven't drove it I fear of breaking anything

[rickpilgrim]

Grinding sound by AC usually means either AC compressor clutch bearing or idler pulley need it with bad bearing. I doubt that the brake light has anything to do with it, brake light usually means there's an imbalance between front and rear brake system and that's a leakage problem.
Of course my 98 has a "loose" e brake pedal that drops down and turns the light on so check that first

[Omana2015]

Okay thanks that what I thought it was but wantes to make sure but would air in the system also cause this light to go on??

[rickpilgrim]

Yes, air is compressible, fluid is not so it would shift the balance and turn on the light.