1977 Mark V Blower Control Issue

Dear Bill,
I just had a new heater core installed and oddly enough the blower motor started to quit. So a new heater core and blower motor were installed. The blower motor will not work in the HEAT position at all ever. Every thing else is fine. As you know when the car is cold and the selector if in the heat position with the fan on it doesn’t come on until the car warms up a bit. The fan will not work in the HEAT position at all ever no matter how far you drive it. The rattle noise it use to make when the heat and blending door opened for floor heat still happens but no fan. My mechanic said there is something else that controls the fan when in that position. Naturally it is now my responsibility to find out what or where it is so he can test it. My suggestion was why not look somewhere between the beginning of the job and the end of the job you did and you will probably figure it out. Do you have any suggestion of what to look for. AS we all know no service station on earth has ever made a mistake (that they would admit to).
Yours,
Chuck
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Hello Chuck –
We have no record that you have recently purchased those heater parts, or any other parts from Lincoln land. The blog information that we offer is for our customers use as we cannot take the time to diagnose problems only to have the necessary parts and manuals purchased from another supplier.
I can tell you that the ” blower cold engine delay” circuit is shown in the Shop Manual along with the wiring diagram. Any experienced shop that is intent on diagnosing and repairing ac/heat circuits should already be well aware of that fact. We do have the necessary shop manuals and other information available for purchase along with the repair parts for your Lincoln. We would be happy to then follow up with any assistance in diagnosing as well with any purchase.
Sincerely,
Bill