Page 1 of 2 12 LastLast
Results 1 to 10 of 11

Thread: 1993 GMC Suburban No heat

  1. #1
    Junior Member
    Join Date
    Jan 2012
    Posts
    6

    1993 GMC Suburban No heat

    I have a 1993 GMC suburban and the heater doesn't work. I hear the blower motor turn when I turn the key to ignition. I also don't see any lights on the air controls also air controls don't work. Any suggestions?

  2. #2
    Senior Moderator chevychase's Avatar
    Join Date
    Oct 2010
    Location
    truck forum .org
    Posts
    16,553
    Blog Entries
    2
    Check fuses to start.. Maybe head unit /control panel. Check for power at unit.
    Will try to find a wire diagrahm.

    Gitter done have fun. Running on empty...running blind...running behind.....
    IF I CAN GET YOU TO SMILE BEFORE I LEAVE.

  3. #3
    Senior Moderator chevychase's Avatar
    Join Date
    Oct 2010
    Location
    truck forum .org
    Posts
    16,553
    Blog Entries
    2

    Gitter done have fun. Running on empty...running blind...running behind.....
    IF I CAN GET YOU TO SMILE BEFORE I LEAVE.

  4. #4
    Senior Member UncleBigBad1968's Avatar
    Join Date
    Dec 2011
    Location
    ne ok
    Posts
    246
    If your thermostat is working, you can feel your heater hoses going into the firewall, both should be realitivley warm. You wont be able to hold on to them for a few min, cuz it will/should be slightly too warm to hold. If one is hot, and the other is cold then your heater core is clogged. Try to flush it first.

  5. #5
    Moderator
    Join Date
    Jul 2011
    Location
    Central Oklahoma
    Posts
    4,333
    If the heater core is clogged best to just change it, if you try to flush it may bust the heater core thus making it leak. Can you change form vent to defrost to floor if so your controls are fine, then the issue comes to the mode door, there are 3 the heat/cold door could be messed up, chevy's are known for this from what i have read, Ihave this issue, a gear inside cracks and gets stuck or won't work, your temp adjustment arrows should flash if this happens. If thats the case its about 100 buck for that mode door motor, but if you can get it out, take it apart the main gear that is/if cracked can be removed turn 180 degrees and put back together to work to get by, this I know did it to mine.
    1994 white ext cab chevy silverado 5.7 rolling 230k miles
    stock with air filter lid flipped,
    open flowing exhaust to a 40 series flowmaster dumped.
    God Bless America, Support our Troops!

  6. #6
    Junior Member
    Join Date
    Jan 2012
    Posts
    6
    Thanks I checked the heater fuse and it was fine. So next step change the thermostat.

  7. #7
    Junior Member
    Join Date
    Jan 2012
    Posts
    6
    Thanks I checked the heater fuse and it was fine. Next step change out the thermostat.

  8. #8
    Senior Member formulabruce's Avatar
    Join Date
    Sep 2009
    Location
    Northern New England
    Posts
    266
    Quote Originally Posted by lclhawnboy View Post
    Thanks I checked the heater fuse and it was fine. Next step change out the thermostat.
    AT least take off the heater hoses and blow through them, please???
    85 K2500, 94 K2500 LD, 04 2500 HD

  9. #9
    Moderator
    Join Date
    Jul 2011
    Location
    Central Oklahoma
    Posts
    4,333
    Quote Originally Posted by formulabruce View Post
    AT least take off the heater hoses and blow through them, please???
    You don't have to blow through the heater hoses, all you need to do is feel of the hoses hen the truck is warm will tell you just as better.
    1994 white ext cab chevy silverado 5.7 rolling 230k miles
    stock with air filter lid flipped,
    open flowing exhaust to a 40 series flowmaster dumped.
    God Bless America, Support our Troops!

  10. #10
    Senior Member UncleBigBad1968's Avatar
    Join Date
    Dec 2011
    Location
    ne ok
    Posts
    246
    If the heater core is clogged best to just change it, if you try to flush it may bust the heater core thus making it leak.

    Never had a leak after I flushed mine. But in case it does then replace it. Might as well save a few bucks, and a headache. It is not easy pulling that dash apart to change the core.

Page 1 of 2 12 LastLast

Similar Threads

  1. 1993 GMC Suburban 1T -4L60E case cracked - What Causes this ?
    By Sparkomatic in forum Chevy Truck Forum
    Replies: 13
    Last Post: 05-01-2012, 11:35 AM
  2. 1993 suburban problems
    By fastgilla in forum Chevy Truck Forum
    Replies: 13
    Last Post: 06-17-2011, 09:11 AM
  3. 1993 chev- no/weak heat w/ heater on, temp falls 195 to 130 then
    By 93bluesilverrad in forum Chevy Truck Forum
    Replies: 2
    Last Post: 05-04-2011, 04:20 AM
  4. 1993 Suburban tranny troubles
    By nate3436 in forum GMC Truck Forum
    Replies: 3
    Last Post: 04-30-2011, 06:24 AM
  5. 1993 SUBURBAN 5.7 - Will not start - Need Help
    By PARKERJOE in forum Chevy Truck Forum
    Replies: 9
    Last Post: 08-05-2009, 10:55 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •