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heater in cab not working

Discussion in 'Chevy Trucks' started by Diesel Freak, Nov 3, 2012.

  1. Diesel Freak

    Diesel Freak Junior Member
    Messages: 11

    i have 2004 chevy silverado 3500 with the 6.0 and the heater is not working checked fuses. all good. replaced heater resistor and the heater controls and still nothing. bench tested the blower motor and that just about jumps off the bench when i put power to it. is there a relay that i dont know about that is hidden somewhere?
  2. magnum1

    magnum1 Senior Member
    from ID & ND
    Messages: 249

    Oops sorry my speed reading and pay attention mode has been deleted
    Last edited: Nov 3, 2012
  3. buddymanzpop

    buddymanzpop Senior Member
    Messages: 603

    Start by checking for power at the plug that plugs into the blower motor with a test light to verify that there is no power to the motor.
  4. Diesel Freak

    Diesel Freak Junior Member
    Messages: 11

    Does anyone know what prong in the the plug for the controls is power and what one is ground? Thx
  5. Diesel Freak

    Diesel Freak Junior Member
    Messages: 11

    ok tested the power at the blower motor plug and got nothing. tested to see if power is at the controld and i got power to the heat/cold plug but i got nothing at the plug for the speed controls. i was told that the power goes to the resister first then to the heatrer controls? is this true or does it go to the controls then to the resister?
  6. brad96z28

    brad96z28 PlowSite.com Addict
    Messages: 1,525

    Your factory harness is melted at the blower resistor. Cant tell you how many ive have done you wont belive me. Also possible the resistor is bad but should still work on Hi. Will need to change pig tail and resistor.
  7. 06Sierra

    06Sierra PlowSite.com Addict
    from Maine
    Messages: 1,329

    I had a 98 with that problem. It ended up being one of the harnesses plugged into the controls on the dash.
  8. DrakeSabitch

    DrakeSabitch Senior Member
    Messages: 119

    x2 on the melted harness. Had mine replaced twice under GM recall. Try whacking it lightly with something, should kick right on if you hit it just right....unless the wires are really melted.
  9. Diesel Freak

    Diesel Freak Junior Member
    Messages: 11

    Replaced plug to resistor found that kit was melted a little but still got nothing? This thing is really stumping me? Does anyone know where the ground is for this circuit? Thx
  10. brad96z28

    brad96z28 PlowSite.com Addict
    Messages: 1,525

    It usually melts the resistor as well.
  11. Diesel Freak

    Diesel Freak Junior Member
    Messages: 11

    Well after work today pulled truck into shop tested and had power at the resistor plug then tested at buttons and had no power. So then I double checked the fuses and power there all good. Went to pull the fuse block out and the blower motor started working. And worked the whole way home. So I guess I would call it fixed. Hope it stays that way cuz the cold weather is here and I think staying for awhile. The for all the info.
  12. 1ATony

    1ATony Junior Member
    Messages: 18

    You have to like those kind of fixes...lol
  13. Paul D

    Paul D Member
    Messages: 37

    OK, so mine doesn't work on five and sometimes doesn't work on 4, but wiggling the switch on dash seems to get 4 working. If it was the resistor it sounds like other speeds wouldn't work but 5 always would work, kinda the opposite of what mine is doing. Hate to throw a resistor at it and hope. :confused:
  14. 1ATony

    1ATony Junior Member
    Messages: 18

    It sounds like it could be a loose connection. You may want to turn the heat on and check the connection to the resistor to see if it's attached securely to it.

    We carry new blower motor resistors on our website with free shipping if yours happens to be bad. Hope this helps you out.

  15. goel

    goel PlowSite.com Addict
    Messages: 1,079

    I had one that works on 1 thru 4, but never on 5. If you pull it apart its probibally corroded or melted. Its an easy check.