Check for a bound up alternator, coolant pump or other pulleys. Also make sure to check the Power Steering pulley for broken edges, they are plastic and with age tend to break
The auxiliary drive or serpentine belt (not timing belt)being lose or snapping
try replacing the vacuum hose from the brake master cylinder to the intake manifold its a 1/2 in hose
Could be a couple causes for this: * the tensioner may need replacing - not keeping enough tension on the "S" belt * worn (stretched) serp belt - replace ~ every 50 or 60k miles.
Check the allignment of all the pully's.
snapping division
the thermostat will make both fans become idle if it is not opening. this happened to me on my 95 3.1 lumina
Check the relay.
Try cleaning the intake manifold.
broken blend door
Old age Frozen or misaligned pulley
it could be a serpentine belt or accessory belt.
A short.