Heater Problem and Horn Problem

chahn48926chahn48926 Member Posts: 4
edited July 2014 in Chevrolet
I have a '99 GMC Suburban with two problems. Problem #1 is no heat from the front heater. Plenty of heat from the rear heater though. I have replaced the control head and the vacuum actutor that controls the valve that supplies hot water to the heater core. The valve moves, and appears to be functioning. Problem #2 it a non-functioning horn. It is not the horn relay or the horns themselves. The problem appears to be in the switch mechanism under the driver's side air bag. How can I remove it to check it?


Charles Hahn


  • smkirk05smkirk05 Member Posts: 1
    I have a '04 Z71 Tahoe. The horn is dying out and I wonder if there is a fuse I can replace or should I take it to the dealership.
  • j2reyj2rey Member Posts: 2
    97 GMC Suburban - the heater/ac fan runs on all different speed settings but after a while (1 hr or so) nearly all air stops coming out any place (not defrost, vent or floor). This happens in cold or hot weather with ac or heater. Sometimes if the cars is turned off and then back on the fan works but it gradually stops coming out on every trip longer than approx 1 hr.
    Thanks in advance for any tips/help!
  • motorpig4motorpig4 Member Posts: 2
    I recently had intake manifold gasket problems and was told to add some "stop-leak" type of product. It didn't work and I eventually had to replace the engine with a new crate 350. That's when my problem started.
    When the mechanic removed the engine, air got to the coolant in the heater hoses and turned the "stop-leak" to an oatmeal consistency. Now the heater core is clogged and no heat is the result.
    My question is, can the heater hoses be taken loose and a pressure sprayer be used to blow the sludge out or will the core need to be replaced(It worked fine before the transplant)?
    Any help would be appreciated greatly, It's cold.
  • okctahoeokctahoe Member Posts: 4
    There is a fuse for the horn, I am not sure which one exactly but my husband replaced the one in his 2001 truck and it took care of the problem
  • danvandanvan Member Posts: 1
    The horn on my wife's '03 Chevy Venture doesn't work. I checked the fuse, and it is fine. Where is the horn located? Are there two horns--in different locations? How do I determine what needs to be replaced?
  • camocavcamocav Member Posts: 7
    I own a 2004 Suburban and I had three problems with my horn due to the contacts were not touching each other, so the dealer had to modify the contacts to touch each other..
  • kspringkspring Member Posts: 1
    I have developed the same problem with my 2001 tahoe. The horn does not work and the front heater will not push out any hot air. please help
  • kiawahkiawah Member Posts: 3,666
    I don't have electrical schematics for your year, but have a factory set for my 2007Sub. The horn circuit basically has three pieces:
    - the horn switchs
    - a Horn PCB relay
    - a 15A Horn fuse

    Check the fuse first, and then the relay, and if you have to get to the switches you have to get into your steering whell behind the airbag.
  • knotts33knotts33 Member Posts: 1
    I cannot locate the horn on my van. It is inop but I have voltage through the relay. Does anyone know where it is so I can check voltage.
  • kiawahkiawah Member Posts: 3,666
    Did you check up in the front grill area?
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