My icemaker started giving me trouble. The ice was freezing into big clumps instead of the individual cubes, and jamming up the whole deal. I figured the evaporator coils must be dust covered and dirty, so we pulled it out. I found huge clumps of dust everywhere behind, and underneath the unit. I took off the back panel to expose the cooling coils and fan, and everything was completely packed with dust!
I vacuumed what I could, (which wasn't much), then I opened the kitchen sliding glass door all the way and put a box fan on "High", blowing out into the back yard. I have one of those portable 5 gallon air tanks I filled to 120 PSI with my air compressor, and blew out the underneath, back, fan, coils, everything. If I could get the nozzle in, it got blasted. You wouldn't believe what came out of there! I hated to do it that way, but it's the only way you can get all of that crap out of there. That was my problem for sure! I've never cleaned it since we bought it about 4 years ago. Now I'll do it every 6 months or so, that way it won't get that bad. It had to be running constantly because of that. It's a messy PITA job, but one you guys might want to think about doing.