Hi My daughters Starlet has had similar symptoms for a month or so, it only squeals when accelerating from low revs with the heated rear window and lights on. Thought it was the fanbelt, but found that the squeal is coming from the crankshaft pulley (harmonic balancer). The outer circumference of the pulley is separated from the inner by a thin rubber strip The bond between them has broken so the outer can slip on the inner when the alternator is loaded. Replacing the pulley doesn't look too difficult assuming it comes off ok, but have had no luck finding a replacement so far. Hope this helps with your problem, be great if anyone can advise on best (cheapest!) place to get a replacement Thanks Dave