Aux Fan Stays On

Okay, after not finding anything in a search, I need some help here.

My auxiliary fan has started staying on after I shut the Jeep down. This occurs intermittently. The vehicle is a 1995 XJ with the 4.0. I know some vehicles do this just as a matter of course, but I had never noticed my XJ doing this before. The last time, it kept running for 30 minutes, so I unplugged the power to the fan.

What is the deal? I don't want to miss that it is running and have it kill my battery.

Thanks for replies,

Morgan

Check your aux fan relay. Maybe it's stuck closed. It's in the PDC which is next to the battery.



K

Correct. Sounds like the exact same thing as I just had happen to my '98. It stayed on so long, it drained the battery. It's the aux fan relay, as the previous post says. Costs about $8 from DCX. Piece of cake. I work in a Lab, so I took the old relay in, popped the top and inspected it at 70X to see what went wrong. It seems that, over time, some solder from the "moving" lead arced across the contacts and deposited onto the opposite lead. That's normal (contacts arc a little when they initially close). But when this deposit built up enough, it actually caused the moving lead to stick (mechanically). Well, $8 is about the cheapest fix I've ever done... so good luck.

Thanks for the info, we'll give it a try and see what happens.