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  1. #1

    Exclamation fan runs with key off!

    have a Q! has enyone had a problem with your fan doin crazy stuff? i will be driving and it will go from setting 2 to 5 full blast! i have to shut the truck off and cycle the switch from off to 5 and it will go off! this is with the truck off!!!!!! also it has happened 2 times where i have went into a stor and i come out and the fan is running full blast! anny ideas thanks~!

  2. #2


    which fan are you referring to? the cooling fan or the blower motor fan?

    the cooling fan will run at times after the car is turned off if the engine still need to cooldown.

    If it is the blower fan you could have a short in the system that is causing it to turn on when you are not in the car. as far as it changing from 2-5 on the blower one of the contacts on the switch could be dirty and might need to be replaced.

    that is defenitly a wierd situation i had a similar thing happen. My A/C would not kick on, it would only come through the passenger vents, but after i shut the truck off it all went to normal.

  3. #3
    Master Mechanic TritonBoulder47's Avatar
    Join Date
    Nov 2009
    Tunkhannock, PA (North East)


    Sounds like your blower motor is starting to go... Pretty soon you'll only have off and full blast, and they'll be reversed (as in 5 will be off and off will be full blast)... LoL

    Tim a.k.a. Da' Boulder

    2003 Chevrolet Avalanche Z71 - Custom Emergency Response POV

    Firefighter, Fire Policeman, Ambulance Driver, Rescue Tech, Emergency Lighting Installer

    Tint, 20's, Bull Bar, Intake, Exhaust, Billet Grill, Stereo, Custom Console, Emergency Equipment, and the list goes on...

  4. #4


    thanks thats what i came up with also but if i keep it on setting 3,4,5 then it is ok but if i cruse around with it any lower it just turns on full blast! posesed!i just make sure it is in the off position then turn off the truck. it seams to be workin right now!!!!! thanks again.

  5. #5


    just an update !!!! after the fan problems NOW MY BATTRY!!!!! read somewhere that if the electronics get to low of a voltage strange things happen thats why most SUVs have big altinators!! put new batt in so hope this was it!!!

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