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Having some problems on my Father's 1997 F150 4.2L V6 manual trans. He's got no heat and is thinking about driving instead of flying to WI next week.
The function selector **** cycles air through dash vents, floor as well as defroster vents. All water lines are warm as should be. The motor does surge a bit when changing positions of the function selector switch yet I cannot hear any discernible vacuum leak.
Could the temperature blend door still be a possibility or should I just start replacing vacuum lines.
I think in 1997 it uses the manual cable door. If this is not the case on the truck in question, then the electric blend door motor is likely faulty. I can;t remember the changeover year.
Anyways even if you were lucky enought to have a pen fall down inside, it still needs to be taken apart. Bummer.....
I should know better than to trust what Pop's tells me. I warmed the truck up this morning and broke out the pyrometer. One line read 117deg and the other 76. Sounds like a plugged heater core.
A plugged core will usually allow some heat at first and then fade away. Even on my old taurus, it was plugged solid, it would still give me 5-10 sec of heat and then fade to zero.
I'll back flush it in the morning. I did pull the motor for the blend door and that seems to be functioning properly. At least that's one thing off the check list. Does this model have a heater control valve? I can't seem to find one listed anywhere in an online search. I'm wondering if that may be stuck shut if there is one.
I'll back flush it in the morning. I did pull the motor for the blend door and that seems to be functioning properly. At least that's one thing off the check list. Does this model have a heater control valve? I can't seem to find one listed anywhere in an online search. I'm wondering if that may be stuck shut if there is one.
Correct..there is no heater control valve in the 97.In essence,the heater core is hot all the time.The Blend door motor assy activates the door according to an electrical feedback from the control on the dash panel.If there is NO heat,I suspect the blend door is remaining closed.Conversely... if there is heat all the time,its stuck open.You could have any of a number of issues...first..heater core plugged up(not likely)..second,the **** on the dash control is stripped,and not sending the proper voltage feedback to the blend door activator assy(plausible) or the blend door controller itself is defective(likely)
Like I said, I'll back flush in the morning. The blend door actuater is working properly and the control **** is not stripped. I pulled that today as well.
You might be able to lay on the drivers floor and look up at the blend motor and see that the arm is moving. If you had the blend door motor off, then you know where its at. Make sure it is stroking the gear box/ arm. With the motor off you can move the door manually and see if the hot air comes out........ vacuum only controls the duct doors and sends the air to the dash ,vent, or floor... Temp is all electric.
WooHoo!!! Once in a while you get lucky. The flush did the trick. Heats is blowing at a balmy 165deg at idle. Thanks for the help, guys. I might just stick around and lurk. Seems to be a friendly place with list of knowledge.