I'm having a hard time finding out what's going on with my son's truck. We thought that he had a leak somewhere in the ac line. "the guy" over at he shop even quoted me $450.00 to repair the line. Another guy said there wasn't a leak and said I needed to take it to a dealer. Well, I found out that the fuse keeps blowing out. So, I figure that there's a short somewhere. How, where do I start testing where the short is. When I replace the fuse the ac runs super cold and works great!!! Help.