Question about 1999 GMC Jimmy

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My 1999 gmc jimmy heater is stuck on heater mode every time, no matter what i do. Please help.

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There is either a linkage that connects to the control box knob,or vacuum lines .If the linkage is off or the knob is broken,it will not switch modes,and if the vacuum controlled actuator has an issue. Remove the trim plate,then remove the control panel by removing the 4 screws,take a look behind it to see if it is broken.

Posted on Dec 30, 2010

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Your control switch is most likely malfunctioning. You will need to replace it. If you are a do-it-yourselfer you can order a used part online from a scrap yard; see eBay Auto. If not, go to your local dealer for replacement. Hope this helps.

Posted on Dec 30, 2010


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1 Answer

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