Contour Enthusiasts Group Archives Forums General Troubleshooting heat on 98 explorer

I know its not a contour but the system should be the same just different components. The problem is with my mothers 98 explorer. The air from the system is always cold. I changed the thermostat as this is the easiest first step. Since that did not work I dug deeper. The vaccum valve under the hood for the heater core opens as it should. The vaccum valve behind the glove box for the ac opens and closes as it should. I disconnected the harness from the top of the plenum behind the golve box and checked the resistance from the temp switch. I get a increase and decrease in resistance as you would expect from the switch.(although not sure what the range should be).I a thinking that there must be some type of blending valve( not sure if that is the term) in the plenum to blend hot air and ambient air. Could this be the most likely cause. If someone with thoughtful insight could chime in I would be most grateful. I live in Maine and this is starting to become an issue. Sorry for the long post but I'm stuck. TIA Rob C

If you have EATC (Electronic automatic temperature control) can do a self-test by pressing the OFF and FLOOR buttons simultaneously and then press the AUTOMATIC button within two seconds. The display will show a pulse tracer going around the center of the display window. The test may run as long as 30 seconds. Record all DTCs displayed.

If you don't have EATC you should check primarily your coolant level, if engine is overheating, plugged or parrtially plugged heater core, temperature blend door binding/stuck, A/C electric blend door actuator.

IT's stupid but i don't know how to post pictures in the forum, tell me how and i'll be able to give you the pinpoint test and electrical schemas

Thanks

Nic.

Nic the truck does not have the elec temp control. The coolant system seems to be fine the truck is not overheating and when the valve for the heater core in the hood opens I can feel the heat transfer through the core. This temp blending valve that you talk about. Would that be the white box ontop of the plenum behind the glove box. As far as pics go they need to be on the web somewhere like fototime or something along that line. When you are on you fototime acc you can click on "create link" it will give you an IP address for the photo. Post that IP address in your post and there you have it. Also in the FAQ of this forum it gives a good how-to on posting pics. Thanks Rob

Thanks for the for the pictures

That might help you. You can start at E6, but recheck the previous ones to be sure.

http://www.fototime.com/inv/A10B84D7086362B

Nic.

It's the blend door, trust me. I have this problem on the Taurus right now, no heat. The blend door is a flapper actuated by engine vaccum that mixed the hot air with air conditioned air. The plastic arm breaks, and in the 2nd Gen Explorer like you have, it's a pain in the rear, because you have to pull the dash apart to get to it.

Goto www.explorerforum.com and search for the blend door. You could have a plugged heater core, but chances are it's the blend door if the system has been flushed recently. I own a 2000 Explorer myself. Great truck. The Taurus has 94K miles and the door is broken, but the Explorer has 147K, and it still works. Silly Fords.