I totally agree with you and that is why I'm handling this myself; I knew there was a chance of this when i decided to to the alarm install. The whole cluster of wires they installed are right there by the fuse box and there are a lot them.
It could be that when the dash harness was moved around, there may have been a strain on the dash circuit board plug causing a bad connection. It's easy to loosen one of those pins in the circuit board.