Thank you so much, that’s really helpful. I just went out and spent a good 30 minutes looking at things. I re-checked the belt tension and it’s definitely ok - it’s not too loose, I can’t get more than half an inch of movement in it even if I push pretty hard. It’s also only 10 months old and there is no fraying or any other signs of wear. I’m a bit loathe to replace a belt that’s virtually new but obviously if I need to I will.
The screech has all but stopped completely unless I start the car completely cold and then it’s soo loud but it does go away once driving. Today, I had things humming along nicely, I can’t see any wobble but a more experienced eye would be able to tell.
But the screech is DEFINITELY related to the air conditioner - when I put it on while the engine is running it screams the place down. There are also two belts - the wider one that goes around the alternator, A/C compressor pulley, water pump pulley etc and then a shorter, thinner one tucked in on the inside of the crankshaft pulley. And that’s pretty much where my knowledge ends. I don’t even know if I’ve got all my pulleys named correctly haha.
I will take a photo as well as try to upload a video of it so that someone else with a lot more knowledge than me can see what they think.
Glasspilot - I was born in the mid-70s but I like to think of myself as young!! 