more 96 heater problems
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Junior Member
Joined: Jan 2011
Posts: 3
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more 96 heater problems
Hello all. Newbie here needing some help please. On my 96, the heater blows fairly warm on the floor, but as soon as you switch it to mix or full defrost, it goes completely cold. Could this problem be in the dash switch or a vacuum motor? I have searched the site for heater problems and did not find anyone with a problem quite like this. Any suggestions? Thanks in advance for any help anyone may be able to offer.
Senior Member
Joined: May 2008
Posts: 162
Likes: 1
if your 96 is like my 90 then it also kicks in the ac compressor when on defrost, i guess it helps defrost better, dryer air. anyway are you getting hot air out of the center vents when the heat is on. worse case is that the heater core is partly plugged.
Senior Member
Joined: Feb 2008
Posts: 4,658
Likes: 28
From: Henderson, NV.
Start at the begining, is the engine up to temp? Are both heater hoses hot to touch? Do you feel the air changing positions, floor,vent, defroster? Do you hear the blend door move when selecting temperature?
Senior Member
Joined: Jul 2007
Posts: 3,805
Likes: 480
From: Cape Girardeau MO
Welcome to the site!
The heater ought to be able to bake you out of the cab. Between the warm air coming out the floor and the cold air coming out the defrost - suggest to take a hard look at the temperature blending damper door.
Not sure when, or even if, this blending door went to being controlled by a vacuum motor - mine is still a cabled set-up - but suggest to remove the glovebox and have a look at the operation of the damper which should now be visible. The glovebox is pretty easy - one or two tabs to depress and a retention cable to pop out, and out the box comes.
Depending on how much you want to fool with this - one suggestion is to just ty-wrap the temperature blending door in the 'hot' position until the weather moderates. Thinking you may have a vacuum leak in one of the damper control lines - which gets to be a real booger to chase down when it's butt-cold.
As ol' Bill recommends - check the heater hoses to ensure you don't have a core blockage or low coolant level, and that the engine is reaching operating temperature.
Good luck and keep us posted. The more information you can feed us, the better troubleshooting we can help with.
The heater ought to be able to bake you out of the cab. Between the warm air coming out the floor and the cold air coming out the defrost - suggest to take a hard look at the temperature blending damper door.
Not sure when, or even if, this blending door went to being controlled by a vacuum motor - mine is still a cabled set-up - but suggest to remove the glovebox and have a look at the operation of the damper which should now be visible. The glovebox is pretty easy - one or two tabs to depress and a retention cable to pop out, and out the box comes.
Depending on how much you want to fool with this - one suggestion is to just ty-wrap the temperature blending door in the 'hot' position until the weather moderates. Thinking you may have a vacuum leak in one of the damper control lines - which gets to be a real booger to chase down when it's butt-cold.
As ol' Bill recommends - check the heater hoses to ensure you don't have a core blockage or low coolant level, and that the engine is reaching operating temperature.
Good luck and keep us posted. The more information you can feed us, the better troubleshooting we can help with.