Alternator belt

[Andy Charles]

Hi all I keep getting a squealing when I start up its had new belts new tensioner but still squeals anyone got any ideas cause the garage don't cheers

 

[solarman216]

Is it a poly-v serpentine belt? if so and it is tension-ed correctly then I would not worry about it if it only happens on early morning startup as the pulley's this time of year will be wet with condensation, if it happens on startup when warm then something is wrong, probably tension, Rick