03 a/c acting up

[jamie72]

the wifes 03 avy,with the auto climate control, is blowing hot air,it only does it at stoplights,ever now and then,as soon as we get moving it cold again,took it to a local shop they charged it again and added 1/2 of freon,then said that the a/c control module is bad.
thats a 250.00 part,i`m ok if thats the prolbem,but just want to be sure and not just throw parts at,anyway is there a way to check it? and if bad where is a good place to buy one??

hey josh where you at buddy...