Noise of belt on my s12.

[burnings12]

Hello! veiled I have a noise of belt on my s12 and I wanted to know if that could announce something or if it is simply because of moisture/wear of the pulley and which A 150.000 km? Also, it is enough bizzare bus has the stop with the idle, I increase power ya no whistle, I put my heating (bottom has because the other position does not function any more for the moment) and he whistles with least acceleration? and the other thing as it is as Ca does not do it everytime has days there or I do not have any noise and I think that is to bind has the humiditer? say to me what you think please I would like to know if Ca can come from of a bearing use who would block? (ha yes the noise vien of the belt connecting alternator and pump water?) THANK YOU, Sorry i'am french