I reckon the icemaker drive motor, which is designed to be on for only a short time, can overheat if the feed mechanism is jammed by built-up ice; that may be causing the high amp draw.
One thing the manual mentions but many people don't realize is that you can limit the frost build-up (and it can get pretty darned substantial) by remembering to shut off the icemaker before hitting the road, and turning it back on upon camping. Make it part of your routine, like leveling, unplugging/plugging, and slides in/out. Just flip the icemaker's wire bail up about 90 minutes before departing. This makes sure that any water in the cube tray is frozen, not liquid. It's water, splashing out from the tray while the coach negotiates turns and bumps, that adds to the frost buildup the most, and can ultimately sieze the mechanism even when the bail-down position still calls for it to cycle.
Regarding defrosting - I believe that side of the system uses 12v. heaters. If your battery voltage is low for some reason, the heaters won't work; but if you're plugged into AC power, the batteries should be up to snuff for defrosting anyway. The unit automatically defrosts the freezer once a day, and if you've set the clock, I believe it defrosts overnight at some hour which I used to know but have forgotten. The thing is, ice build-up from road splashing is likely on mechanism and freezer parts that aren't along the wall surfaces where the defrost heaters work.
You can force a manual defrost cycle anytime by switching OFF the refrigerator with the ON/OFF button; then press and hold the AUTO/STORE button and press the ON/OFF button; "dE Fr" should come up on the display. That said, I've found that the extra defrost cycling simply won't work if there is already too much ice built up, esp. away from wall surfaces as I mentioned previously. You just have to do it the old fashioned way - chipping and melting. But be careful you don't scratch or harm something while doing any chipping. It's best to keep an eye on the icemaker regularly, and not let it build up in the first place.
There is, of course, the chance that there is some other cause for the icemaker overload, and defrosting may not correct it; perhaps a fault in its circuit board or a short in the circuit somewhere.
Joel