Jeep was overheating because the fan wasn't coming on. Unplugged the fan, and ran it straight from the battery and nothing. Took out the fan, and it was spinning fine so I took off the cover. Found out the brushes weren't making contact, since they were frozen in place by 175k miles of crud, and not to mention sand. (oops, how did that get there?) Pried out the brushes, cleaned them and hosed everything down with some silicone spray, and works perfectly now. Keep this in mind if your fan stops working.