HVAC only has cold air not heat, signal not getting to blend door actuator

1999 FORD EXPLORER
19,900 MILES
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FIGHTFAIR99
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I have a major issue with my heat and it's taken down three mechanics already. Nobody can seem to figure it out. Any help from an experienced person would be greatly appreciated.

I have a 1999 ford explorer limited , v8, with automatic heat controls and I only have cold air. Long story short, the signal isn't getting to the blend door actuator which in turn can't close the blend door.

Does anybody know know what next to replace?

Thank you
Nov 20, 2012 at 2:52 AM
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ASEMASTER6371
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not until the failure is determined.

what have the other guys done???

the hvac control unit sends signals to the blend door motors when info recieved demands it. the ambient temp sensor, coolant temp and many other factors are involved.

a shop with a scan tool can look in the system for faults.

Roy
Nov 20, 2012 at 3:05 AM
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FIGHTFAIR99
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The first mechanic thought it was the thermostat as when I lived in florida the local shop "florida-ized" the car by changing the thermostat and putting in a larger radiator. Now the thermostat and the gauge are working great with a good flush done as well.

The 2nd guy thought it was the temp control valve but then said it wasn't and it was the actuator.

3rd guy thought it was the temp control panel. still no heat

Is there something else a Florida mechanic would do to keep the blend door from closing like a fuse or something?

Nov 20, 2012 at 3:15 AM
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ASEMASTER6371
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nope. you need someone more experienced with this system. it is a complicated system but with a scan tool and a good tech, they will get to the bottom of it.

i think you have a bad blend door actuator. to confirm it, it needs to be moved manually to verify it can get heat.

Roy
Nov 20, 2012 at 3:23 AM
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HOMER1967
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i would suspect a bad blend door actuator,it is a very common issue for these trucks,i do 6-8 of the a year.do you hear any type of clicking noise from under the dash?as already stated,a competent and well equiped tech should be able to get to the route cause whatever it may be.
Nov 22, 2012 at 1:25 AM
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RONNANGIEHIL
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how much time is involved in replacing to blend doors and or the actuator, and trouble shooting them
Dec 13, 2019 at 1:27 PM (Merged)
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IMPALASS
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Hello –

First, can you let me know if you have a 4.0L SOHC VIN E or 4.0L VIN X for the engine? The VIN is the 8th digit of your vehicle VIN number.

Next, why do you think your blend doors etc are bad – what is going on with the vehicle, no hot air in the passenger area?
Dec 13, 2019 at 1:27 PM (Merged)
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RONNANGIEHIL
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[quote:1e83dcfe45="ImpalaSS"]Hello –

First, can you let me know if you have a 4.0L SOHC VIN E or 4.0L VIN X for the engine? The VIN is the 8th digit of your vehicle VIN number.

Next, why do you think your blend doors etc are bad – what is going on with the vehicle, no hot air in the passenger area?

Thanks for the donation

Please let us know if what the final fix was for your car so we can better assist others. Thanks!

Find a car repair manual for your car repair questions.[/quote:1e83dcfe45] the truck has both heator hoses hot, when i turn the switch from hot to cold and back i can not hear any noise from under dash the dealer says that the blend doors and the acctuators go bad usuly can you tell me how much time to r and r the heator box to get to the blend doors
Dec 13, 2019 at 1:27 PM (Merged)
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IMPALASS
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Hello - There are several doors - I have provided a quote for time per your request. It also depends on your mechanical abilities. I have also attached two TSBs about discussions on this. Hope this helps. Article No. 99-8-8 05/03/99 CLIMATE CONTROL - ERRATIC OR INSUFFICIENT TEMPERATURE CONTROL - EATC EQUIPPED VEHICLES - SERVICE TIP LIGHT TRUCK: 1995-1999 EXPLORER 1997-1999 MOUNTAINEER ISSUE Concerns of erratic or insufficient temperature control, where temperature control does not match setpoint, or where temperature gradually wanders away from setpoint have arisen. These concerns may be caused by various items that are listed in this Service Tip TSB article. ACTION Follow Service Tips indicated to aid in normal diagnosis of the Electronic Automatic Temperature Control (EATC) system. SERVICE TIP Refer to the following diagnostic procedure according to the symptoms listed if no Diagnostic Trouble Codes (DTCs) are obtained from the EATC self-test, which should be performed prior to any other diagnosis. Vehicles with "No/Erratic temperature control," or "System works in Auto, but not in Manual mode" symptoms: Drive actuator in both directions while visually checking actuator for movement. 1. If there is movement, remove actuator and visually che6k blend door where the actuator rod inserts for cracks. The instrument panel does not have to be removed for this operation. If the door is cracked, order a service plenum. Refer to the Service Plenum Tips in this article. 2. If there is no movement, diagnose system according to pinpoint tests in the appropriate Explorer/Mountaineer Workshop Manual. Vehicles with "System does not maintain setpoint temperature" or "Setpoint is reached but system gradually cools" symptoms: Inspect the in-car temperature sensor aspirator tube for proper connection at both ends. Also check to make sure the in-car temperature sensor housing is attached to AND FIRMLY seated to the dash panel. The sensor is mounted on two (2) pins. It is possible for the sensor to be attached to the pins but not seated against the dash panel which will cause this symptom. EATC ASPIRATION TEST This test will determine if the In-Car Temperature Sensor (ICTS) is receiving enough aspiration. A lack of aspiration can result in an incorrect ICTS reading and cause the automatic temperature control to act erratically with symptoms like: EATC blowing too cold or too warm. 1. Cut a piece of toilet paper or tissue paper about 2.5x2.5 cm (1x1") (paper towel will not work). 2. Turn the key on, turn fan speed to HIGH BLOWER, select PANEL or VENT mode. 3. Place the piece of tissue paper over the aspirator grille opening, if aspiration (suction) is present, the tissue paper should "stick" to aspirator grille. 4. Slowly lower the fan speed to LOW BLOWER. The tissue paper should still "stick" to aspirator grille. 5. Turn fan to HIGH BLOWER, then turn fan OFF. Tissue paper should fall off. 6. If the tissue paper falls off the aspirator grille when the fan is ON: a. Check that the aspirator hose is properly connected at both ends (at plenum case and ICTS). b. Check for proper size aspirator hole in heater plenum (19 mm (3/4") 1999 model year only). c. Check that the ICTS is properly sealed against dash panel with no gaps. d. Check for kinks and cuts in the aspirator hose. e. Repair as needed. Other ^ Check for proper operation of the heater water valve. Visually inspect vacuum hose for kinks, leaks, or disconnects. ^ Temperature differentials between panel and floor vents in mix modes and temperature setpoints that are not at full cool. Setpoints not at full cool or full heat may exist and are a normal concern and not repairable. SERVICE PLENUM TIPS This procedure applies to 1995-1999 Explorers when service of the blend door/plenum or actuator is concerned. The following applies to EATC-equipped vehicles: 1. 1998 and 1999 blend door actuators are electronically different than 1995-1997 blend door actuators and cannot be interchanged. 2. The service plenum for 1995-1999 model year vehicles is the 1999 model year Plenum (F87Z-18471-DA). 3. The service plenum may be different from the plenum being removed from the vehicle in the following ways: a. The service plenum has the blend door actuator mounting bracket molded in the plenum. If you have a new or original actuator with the mounting bracket attached, remove the bracket and discard. b. The service plenum will have a hole about 19 mm (3/4") diameter near the heater core cover. This hole is the location for the aspirator tube connection on 1999 model year vehicles. If the service plenum is installed on an earlier model, this hole should be plugged. c. The service plenum has a nylon blend door which is stronger than the ABS plastic door installed on vehicles built through April 1998. 4. When installing actuators on the plenum, there will be pressure on the door if the actuator is driven to full heat or full cold position. This is necessary to seat the door and is not the cause of blend door breakage that occurred on earlier vehicles. Driving the actuator to a midrange position will allow easy installation of the actuator. Article No. 98-23-20 11/23/98 FORD: 1997-98 CROWN VICTORIA, TAURUS LINCOLN-MERCURY: 1997 TOWN CAR 1997-98 CONTINENTAL, GRAND MARQUIS, SABLE LIGHT TRUCK: 1997-98 EXPLORER, MOUNTAINEER This TSB article is being republished in its entirety to remove reference to the 1998 Town Car. ISSUE Some vehicles with a very low odometer reading may experience a lack of temperature control. This may be caused by the incorrect blend air door actuator being installed during the manufacturing process. ACTION Install the correct blend air door actuator. Refer to the following text and Actuator Chart to determine if the correct blend air door actuator is installed on the vehicle. Vehicles which are equipped with manual and Electronic Automatic Temperature Control (EATC) use different actuators. The actuators are marked "MAN" for manual and "EATC" or "ATC" for EATC systems. These markings are found on the part number sticker on the actuator. 1998 actuators differ from 1997 actuators on some vehicles (Crown Victoria/Grand Marquis, Continental, Explorer/Mountaineer) and are not interchangeable. Installation of the wrong actuator can cause potentiometer failure on manual systems, and no temperature control for both manual and EATC systems, as well as Diagnostic Trouble Code (DTC) 24 or 25 on EATC systems.


https://www.2carpros.com/forum/automotive_pictures/248015_Picture10_4.jpg

Refer to the Actuator Chart to determine if the correct actuator is installed into the vehicle and service as required.


https://www.2carpros.com/forum/automotive_pictures/248015_Picture11_3.jpg

Parts Block OTHER APPLICABLE ARTICLES: NONE SUPERSEDES: 98-10-3 WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage OPERATION DESCRIPTION TIME 982320A install Correct Blend Air 2.3 Hrs. Door Actuator (Crown Victoria/Grand Marquis) 982320B Install Correct Blend Air 0.7 Hr. Door Actuator (Taurus/Sable) 982320C Install Correct Blend Air 1.2 Hrs. Door Actuator (Continental) 982320D Install Correct Blend Air 2.5 Hrs. Door Actuator (Explorer/Mountaineer) 982320E Install Correct Blend Air 1.2 Hrs. Door Actuator (Town Car) DEALER CODING CONDITION BASIC PART NO. CODE 19E616 12 OASIS CODES: 208000, 208100, 208200, 208300, 208999
Dec 13, 2019 at 1:27 PM (Merged)
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SPIKENBUDDY
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My 96 ford explorer needed a new Blend Door Actuator so i took out the old one and i test the new one and it burn up and it did not work what do you think what is going on now.
Dec 13, 2019 at 1:27 PM (Merged)
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JACOBANDNICKOLAS
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The blend door has an obstruction not allowing the door to move. This happens when a pen or something gets dropped down a vent.
Dec 13, 2019 at 1:27 PM (Merged)
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WOOGLES
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I was able to get acuator off and saw that it was rotating with temp knob movement. The top of the temp blend door is broken, half of it is missing. Is there an easy way to replace this door or is the only way to remove the dash and access the box it is in and replace it?
Dec 13, 2019 at 1:27 PM (Merged)
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BEERGUY
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It depends on whether the shaft is totally broken off the blend door or just partially. If there is a partial shaft there is a fix where you can drive a small nail through the actuator shaft and reinsert it and it will get enough purchase around what's left of the shaft to work.

If the shaft is totally broken off the door, then you will need to remove the box.
Dec 13, 2019 at 1:27 PM (Merged)