Baystate Jeepers

2002 KJ, had it for a couple months. Occasionally ran warm, couldn't figure it out. Until today. Overheated on the highway and found the electric fan is pushing the air backwards. It's pushing the air from the engine, through the radiator and out the grill. Which has been ok in slow traffic but at higher speeds it negates the cooling effect, or that's what seems to be happening

Haven't had a chance to put a DVM on it to see if the voltages are reversed but idling doesn't get it warm enough to warrant the fan coming on. And looking at a wiring diagram, I don't see how the voltages could possibly be reversed. Is it possible an electric fan could reverse direction? I wanted to disconnect it from the relays and jumper it to the battery but I ran out of daylight. Figured I'd phone a friend and sleep on it until tomorrow. And see what the experts have to say

If you turn the ac on the fan will come on. A bad relay can cause it to run backwards but not very common.

Thanks! I'll check that