I was interested in same topic because of my artical about Georg Amon and US raid against Messina on June 25, 1943.
This overview gives reference to radar stations at Sciacca, Marsala and Licata. Some more radar sets were probably mobile ones.
http://www.milhist.net/usaaf/mto43b.html
... 4th radar location in Sicily known to me is Trapani, but that is generally known.
cheers