Jeff.
I had a problem with my 2193 Dometic
refrigerator while on my Alaska trip. It was doing exactly what you are describing after having been on very dusty roads. It never got hot enough to do it's chemical thing. I could hold my hand on the mechanism, should be too hot for that normally.
The solution was:
1. There is no flame adjustment on the 2193
2. Blow out the line and jet, which really didn't seem to have much dust/dirt. Didn't help.
3. Checked the propane pressure with both the stove and refrigerator on. The pressure was 9......it should be between 10 and 14.
4. Replaced the regulator, $19 and now the pressure is 12.
Refridge works great....like new.
The problem seemed to be that the regulator was facing horizontal instead of vertical. That allowed dust/dirt to get into it. Make sure your regulator is facing down.