Aircondition Fan Running with Ignition Switch Off

Hi guys,

Same 98 Express 3500 with 423,000 miles and a new problem. I shut the van off the other day and pulled the key out of the switch and as I was getting out I realized that the fan for the air conditioner was still running. If I turn the master air conditioner selector knob to the off position the fan stops. I replaced that master control pannel about two years ago. Would this be a failed or failing ignition switch or is there a relay that powers that control pannel that might be failing? It only does this every once in a while so it seems more likely to be a bad relay. If it is a relay any idea where it is located?

Thanks again for all your help MT-2500


Wayne Mann

Hi guys,

Same 98 Express 3500 with 423,000 miles and a new problem. I shut the van off the other day and pulled the key out of the switch and as I was getting out I realized that the fan for the air conditioner was still running. If I turn the master air conditioner selector knob to the off position the fan stops. I replaced that master control pannel about two years ago. Would this be a failed or failing ignition switch or is there a relay that powers that control pannel that might be failing? It only does this every once in a while so it seems more likely to be a bad relay. If it is a relay any idea where it is located?

Thanks again for all your help MT-2500


Wayne Mann



You are welcome.
If switch off is turning everything else off I would go for relay first.
For a stuck relay test tap on top of it.
Reminds me of a little old lady customer I had one time.
Hers had a bad habit and would do that when she went out to high class resturant in her Cadalic.
Her solution was pop the hood and jerk off her high spike heal shoe and give the relay a taste of her spike heal. :lol2::rofl::grinno:
Also.
I could always tell which relay that was the problem by the spike heal marks.
Good Luck and let us know how it goes.

AC blower motor relay is at/near HAVC control panel.
Also there is a AC enable relay in under hood relay/fuse box.

Thanks MT-2500. I will check the relays today if I can get it to do it again.


Wayne Mann