Blower motor

Discussion in 'Engine Performance + Maintenance' started by Dennis Wilkie, Oct 12, 2019 at 7:33 PM.

Car Parts
  1. Dennis Wilkie

    Dennis Wilkie OBS Enthusiast

    Messages:
    55
    Likes Received:
    5
    Joined:
    Jun 23, 2019
    Location:
    Arkansas
    I just noticed my blower sounds like it's always on even when it's not supposed to be. My fan won't actually kick on and blow unless I switch it on high, but it sounds like there's always something running in that general area even when it's off, and the heater/ac lights are weirdly selective on when they want to illuminate. Any ideas on what that might be?
     
  2. Schurkey

    Schurkey I'm Awesome

    Messages:
    996
    Likes Received:
    392
    Joined:
    Jan 14, 2018
    Location:
    The Seasonally Frozen Wastelands
    WHAT VEHICLE?

    When my '97 K2500 had no blower speeds except "high", the blower resistor assembly had a failed thermal fuse. The thermal fuse is "not replaceable" separately, so a new resistor assembly was obtained from the Treasure Yard, which fixed the lack of lower speeds.

    Beyond that, I have no idea what might be running over there. A failed air-door actuator?

    My '88 K1500 has the goofy electro-flourescent-thingamajig display for the heater/AC. The thing doesn't work as often as it does; and I've had it apart twice to re-flow solder on the display board (which absolutely, positively fixes the problem...for about six months.) I finally discovered a spot on the front, which if I apply pressure with my thumb, revives the display for minutes or hours.
     
  3. 98 Nitro

    98 Nitro I'm Awesome

    Messages:
    123
    Likes Received:
    22
    Joined:
    Apr 10, 2017
    Location:
    Indiana
    When mine was acting up last year in winter I replaced the fan switch, and while out replaced the 20yr old finicky bulbs. Sometimes you have to replace the whole panel, or as Schurkey said the resistor.
     
    Last edited: Oct 12, 2019 at 9:18 PM
  4. Dennis Wilkie

    Dennis Wilkie OBS Enthusiast

    Messages:
    55
    Likes Received:
    5
    Joined:
    Jun 23, 2019
    Location:
    Arkansas
    It's a 92 k1500 4x4, aside from the engine transmission and rear end. Forgot to add that part, lol. I had a feeling it was in the general area of the actuator or a stuck vent based on everything i've read from other people having similar problems. I'll probably get out there and see what I can figure out after the power fully drains. Had to reset my ecm for an unrelated issue
     
  5. Gramps

    Gramps I'm Awesome

    Messages:
    122
    Likes Received:
    88
    Joined:
    Aug 24, 2012
    Resistor is toast if you’ve lost everytbing but high.
    And I think if I remember right gm had it so even when the heater was “off” the fan would still run just a little like half the speed of the low setting, to circulate the air.
     
  6. Dennis Wilkie

    Dennis Wilkie OBS Enthusiast

    Messages:
    55
    Likes Received:
    5
    Joined:
    Jun 23, 2019
    Location:
    Arkansas
    Switched out the actuators and resistor, and it's doing the exact same thing. No difference whatsoever.

    20191014_182436.jpg

    20191014_182500.jpg
     
  7. east302

    east302 I'm Awesome

    Messages:
    1,754
    Likes Received:
    550
    Joined:
    Oct 4, 2013
    Location:
    Jackson, MS
    Here are the diagnostics for a 98. The general function is possibly the same for a 92 (resistor plus relay for high speed) so maybe it will help.

    A26AEA1D-71DA-456E-BF17-FF659C9F51E1.gif

    32314CC8-0A97-4963-95B4-3D388DCCA72D.jpeg

    F9D57953-6091-4F3F-BC08-1B868CC915B0.gif

    6F10FBB4-380E-499F-BF53-4A0943B343CF.jpeg
     
  8. Schurkey

    Schurkey I'm Awesome

    Messages:
    996
    Likes Received:
    392
    Joined:
    Jan 14, 2018
    Location:
    The Seasonally Frozen Wastelands
    Yes, that's the blower resistor assembly.

    No, those are not the air door actuators. Those are relays. The air door actuators look like little pianos
     
  9. Dennis Wilkie

    Dennis Wilkie OBS Enthusiast

    Messages:
    55
    Likes Received:
    5
    Joined:
    Jun 23, 2019
    Location:
    Arkansas
    I'm well aware of what the actuators are, and yes I changed both of them. Those were just some extra relays I grabbed from the same truck just in case
     
  10. superdave

    superdave Proud NOOA Member

    Age:
    55
    Messages:
    637
    Likes Received:
    170
    Joined:
    Jan 26, 2013
    I fought an on again off again war with my fan and switch for years. Finally figured out that the wiring harness that plugs into the switch had overheated and melted/softened enough to move the pins and make the connection iffy. I have replaced the fan switch twice, put a whole new control panel in, replaced the blower motor (it was bad), replaced the relay and resistor. Finally figured it out because while I was getting 12v at the fan when checking with a meter, it would barely make the circuit tester light up at all. The connection was bad.
     

Share This Page