Check all the connections to you instument panel and also the printed circuit board of the IP as I have seen the odd one that has a bad connection that when it heats up there is too much resistance causing it to temporarily crap out and I have also seen the same thing on the printed circuit boards... just a place to start off the top of my head since there is more than one problem...also check if they share the same fused circuit? maybe a problem somewhere else like even a bad fuse connection?