I see a lot of threads for alternators destroying belts, but not in this manner: It looks like the belt melted while it was not moving. It’s melted in the one spot it had been touching the pulley, then broke as I was driving to work. No other obvious damage to belt.It looks like the pulley became so hot that it melted after the car was shut off. The alternator spins freely. I did notice the battery had a little acid around the ground post. I believe the angle is correct ( Yes Styx, the washer is on the right side. See have been reading up!). The belt is only damaged in the one spot. Could anything other than friction cause the pulley to get that hot? It was a basic autozone type belt, duralast I think, that was just a few hundred miles old. Could the battery have been overcharged or caused this by being bad? Tested ok, but will replace as part of the repair.

Oh! The car is an FC T2, 89 model. Thanks for any input.

 

Is your water pump spinning freely? Is this a single sheave pulley?

 

alternators can get extremely hot, i'm not sure what would cause one to get so hot to the point that it melted a belt though, you could get a temperature gun and monitor the alternator's temperatures to see if it is getting abnormally warm.

if it is the alternator getting that hot, i'd suspect it is constantly full field, meaning your charge cable is going bad or the bearings are starting to go south.

 

Before it failed, did you see the "battery" or charging light lit up next to the clock? Was the engine getting hot/close to overheating?

Usually when the belt is worn through in a single spot,it means that the belt was stopped but the crank was spinning. This happens when the engine is running, the belt and one of the accessories has stopped, so the belt just slides on the crank pulley, heats up and melts. If the belt were spinning with the crank, the wear from slippage would be evenly distributed around the whole belt. Could something have jammed the alternator or got wedged between the belt and alternator, keeping them from spinning?

 

Do any of the pulleys have wear on one side or the crank pulley look like it was spinning on the belt?

 

Are you still running the air pump on the engine? After I removed mine I had to upgrade to a dual pulley on my alt cause I was only running 1 belt to water pump/alt after removing the airpump.