QuestionQUESTION: Just getting very minimal heat (low temperature, just warm) flow through interior vents.
Following your previous troubleshooting advise, I:
1. Checked and confirmed hoses to/from radiator are hot and about same temperature. The cooling system was recently flushed and new thermostat (180 degree) installed.
2. Inlet and outlet heater hoses are hot and feel about same temperature.
3. Pulled the heater controls from the interior panel and looked at the gears and cable for the blend door which all appear fine and working correctly.
I'm lost as to want to check next to fix this problem.
ANSWER: Hi Gary,
If the heater hoses are not only equally hot and truly hot (should feel like the radiator hose temps), then the core is open. If the mode door is working and air is going in the various directions as requested, then the path should switch away from the defroster and of course the ac compressor should stop (it only runs when you ask for defrost (if you haven't asked for ac :)). So that leaves the blend door. The cable may be attached but the door could be jammed or the tab that moves it broken or for some other reason too much of the incoming air is going over the ac evaporator core and too little over the heater core. So that is where I would suggest you focus your attention.
Roland
PS Please 'rate' my answer and consider nomination. Thanks
---------- FOLLOW-UP ----------
QUESTION: Thanks for the very quick and useful response. Can you direct me to a source that explains the best way to get to the blend door? My Haynes manual really isn't helpful in this area.
Also I'm going to recheck the heater hoses for temperature to make certain they are similar to radiator hoses. If they are not, say somewhat cooler, then what?
AnswerI'm only 2 nominations behind!
Please 'rate' my answer below, and thank me with a "Yes"
The deadline is Thursday the 31st at 4 pm CT
Your help is most appreciated, Gary
Hi Gary,
If the hoses aren't as hot as the engine/radiator hose then I would suspect that the core of the heater is partially clogged and so you would want to remove the hoses at the engine and back flush the core with a garden attached to the output side of the core.
The blend door is on the front of the unit just above the tunnel. You evidentally watched it move in response to changing the temp control knob. Here is how I earlier described adjusting that cable in case the door is not moving through its complete range of motion to another owner who was having trouble getting heat:
"There is a cable from the temp control to the door that is decoupled, most likely.
To get to all this you begin by removing the bezel around the control panel and radio. Then there are three screws for the cluster hood to remove and two screws for the ventilation control module to remove. You may also have to remove the cubby bin/cigar lighter bezel which is held in place by a couple of screws. Remove that bezel and wiring.
You should then be able to pull out the control module and disconnect the wiring plug for it. Then you will see a cable from the temp control that goes to the temp door lever. The plastic arm to open/close flow through the heating core may be broken at the point of attachment for the cable to the temperature selector on the climate control module. Or the clamp on the outside sheath of the cable may be unclipped from its attachment to the module and thus the cable is not moving the actuator arm to the heat position, thus no heat. So adjust the cable in the clamp so that when it is attached you get the full range of motion of the lever. If you still don't have heat let me know and I can xerox a couple of pages from the manual that show how to deal with the cable for the temperature door."
The manual only shows removing the door after the whole unit is removed, which is a very big process I could best communicate via postal mailing you a xerox copy. There are 8 pages that show the entire unit and its disassembly, or I could just send one page that show the blend door being released. If you want the 8 I would do those with the understanding you would send me back 3 44-cent stamps to cover the copy and mail cost. I will send the 1 page at no cost.
Roland
PS: Thanks for the kind rating and nomination.
