Need some help Heavy D

I have a fleet of 2007 International 9400I's and I recently added a 2006 to it. This truck sat quite a bit, has lower miles. I keep having trouble with the gauges in the dash. First off, I keep blowing the Qualcomm ignition feed. As soon as you put the fuse in, it just blows it. I have the qualcomm completely disconnected in the sidebox, so I'm unsure what is going on. So I have had this truck to a good shop and they thought it was fixed but it's doing it again. This truck has already fried one cluster and I would hate for it to happen again. What happens is sometimes it works fine but other days the gauges will peg to 6:00 and some of them act like they are stuck. The dash will read no datalink. I know these have problems at the wiring harness where it goes over the motor but would really hate to dig in unless I really think that is the problem. Do you have any advice Heavy D or anyone else, I could sure use some. Thanks