If you open the hood, look over, above and to the left
(your left not the trucks) of the master cylinder you'll see the throttle cable attached to the throttle potentiometer.
Using a needle nose plier carefully grab , twist and pry up the ball socket off the stud. Clean out the old grease and dirt, lube with your favorite grease, reattach. It the throttle feels "sticky"
it could be the cable itself. You can use a motorcycle cable luber or buy a new cable.

Open up the fuse panel under the hood. Easiest way with out breaking the tabs is to apply pressure to the tab and slap down on the cover with the ball of your other hand. This compresses the seal enough for the tab to release. look at the diagram and
see which fuse is labeled for the aux fan. Pull it out and inspect
it. if it is open(blown) sepperate teh 4 pin connector at the
aux fan, if there is water present then blow dry adn pack the connector with dielectric grease and reassymble with another
30 amp fuse. If it occurs again you have a bad motor or
need the updated harness(free if your still under warrenty).

50% of all ML's are running around with blown aux fan fuses.

Emmett.