Thanks for reading and hopefully someone has an avenue I can persue: I have a 1993 Silverado recently purchased to pull my camper and I notice the air blows at less than optimal. It seems like I'm on low speed even though I can tell it's on high. Is there somewhere I can go in the heating system to look for a blockage? It's really noticable when in fefrost mode. I'm very familiar with taking apart dashes due to being a professional car stereo installer but I really do not want to take the entire dash apart if it's not necessary. Thanks in advance for any suggestions.