Need location of heater control valve-'89 Buick Park Ave 3800

Discussion in 'Domestics' started by JackC, Nov 20, 2010.

  1. JackC

    JackC wrench

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    Hi to all and Happy Thanksgiving:

    Yesterday my heater would not produce cabin heat.

    So far I have discovered:
    1. All 5 vac actuators hold vac. and the doors open and close.
    2. I have no fault codes on my '89 Park Ave Electronic Touch Climate Control.
    3. The blower works fine.
    4. Engine does come up to normal heat range.

    Therefore, I suspect the heater control valve, but have not been able to locate it. From the parts catalogs I know it is vac actuated and the hoses go in and out on a 90 degree angle. One hose end looks to be threaded and the other a slip on fitting.

    I see 2 coolant hoses going through the firewall, but no heater control valve in the engine compartment. Looking under the passenger side of the dash, where the hoses would come through (after removing the protective panels) I do not see the hoses or heater control valve.

    I looks like maybe I have to open up a black plastic box that may be the heater core and the heater control valve.

    Anybody know what I need to remove to get to the valve and where it is for sure, before I take too much apart or break something???

    Thank you , Jack
     
  2. JackC

    JackC wrench

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    Added info:
    I have no heat to the heater or defroster. I may be wrong in condemning the heater control valve. I read that most valves fail to fully open default so that the defroster will still work for safety reasons. But some fail to closed.

    Anyone know if an '89 Buick Park Ave 3800 heater control valve fails to open or closed??
     
  3. nickb2

    nickb2 Wrench. I help when I can

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    access the controls behind the glove box and there is a metal rod sitting on top of a black box right behind the glove box. This can come undone. If you move the rod back and forth you can control the temperature of the air. If this is ok you may have a head unit issue. I think you can pull service codes from these like caddys. Maybe some of the american techs can help more. Here is an image I found of vacuum assembly.

    [attachment deleted by server]
     
  4. JackC

    JackC wrench

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    Nickb2:
    I see the rod, but can not move it manually. It is attached to a lever on top of the big black box that I assume opens a blend door inside the black box. The other end of the rod appears to be attached to a rectangular little box with a circuit board inside of it. I assume that is what actuates it and is what you call the "head unit".
    Should I warm up the engine, turn on the heat and see it that rod and lever move?
     
  5. Gus

    Gus wrench

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    There is no heater control valve.......

    As Nickb2 states, the black box is the temp door actuator....it drives that metal rod.....the metal rod is attached to the lever for the temp door.....all you have to do, is drop the glove box, and start the car, and then adjust the temp from coldest(60) to the hottest(90).....

    The actuator should move the rod.....if it doesn't, pop the rod off the lever to the temp door......now manually move that lever from one end to the other.....if you now have heat, the temp door is ok......probem is the the actuator motor OR the control head.....

    As a quick fix for heat, duct tape the lever in the heat position, so you will be warm......

    If temp doesn't change when moving the lever, the door is broken......

    If lever doesn't move, the door is jammed.....
     
  6. JackC

    JackC wrench

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    Gus: Thanks. Great info.

    I will investigate and let you know. I hope it is as you described. Sounds easier than replacing the heater control valve, if it even has one.

    It is strange that every parts catalog I looked at listed a heater control valve for my car. Then the parts stores catalogs seem to eliminate it in the early 90's. Are you sure that mine would not have one, or might you be thinking of a newer model? This is an '89.

    PS: It just dawned on me. Probaby the heater control valve is for '89 cars without the electronic controls.

    JackC
     
  7. Gmolds66

    Gmolds66 I'd rather be flying!

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    Hello JackC,

    I had the same problem in my wife's 1997 Olds Regency and did the duct tape trick... It worked! Don't forget to reverse the procedure for summer / ac driving conditions.

    Gmolds66
     
  8. JackC

    JackC wrench

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    Gmolds66:
    Good to know. I think I discovered the problem. A tube of hand cream had fallen out of the back of the glove box and jammed into the linkage. After removing that, it seems to be working just fine.
    Too bad I didn't look there first instead of last. Live and learn. Yep still doing that at 77 years old. Now I will go and put the underside of the dash back together.
     
  9. nickb2

    nickb2 Wrench. I help when I can

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    Funny the crp you find that does weird stuff. I was working at dodge and a lady comes in with CD problems, won't even turn on. Fuse keeps shorting. This Cd player had 4 $$ in change stuffed into it by one of her kids who played slot machine with it. Sorry lady, not covered by warranty!! Was an easy diagnosis when I pulled the unit out and felt it heavy and shook it, quarter dropped out. :ROFL Don't tell the mother, but I grabbed a 1$ for my pepsi break. Only found 3 $$ missus!! :ROFL
     

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