2012 GC Heated Seats Not really working

In my 2012 Grand Cherokee Limited, the front heated seats warm up a little but not very much. The switch light shows high/low but I can leave it on the high/max setting for 4 hours and it nearly warms up. I went to my mechanic and had it scanned and all seats have power, all switches operate properly but the seats only warm to a max of 60 degrees F. To me it seems system only recognizes the lowest setting and not the max setting. Does anyone have any suggestions what the issue might be? what is a normal temp for a seat on the max setting? I'm told they either work or they don't.