New to the Jeeping (again). I have a 2005 Wrangler with the 4.0. I’ve done some research and found that my AC only blowing out of my defrost is a result of a vacuum leak. There is no obvious leak and changing out the switches didn’t solve anything (the blower resister was bad too and I changed it, but before changing it, I swapped the switches hoping to fix both issues. I’ll be sending the switches back). What is the best way to find the vacuum leak? Is there a good trick to find the leak? Is there a tool that I should buy?