Hello I have 2002 f250 7.3 diesel has no
heat blows only one speed and through
defrost but cold would this be vacuum leak
or heater exhange motor thank you in
well....to me it sounds like the blower resistor pack is fried~...because this will only give you "full speed ahead" and none of the lesser speeds~ shopping for it can't find any...will try different search engines...as far as a vacuum leak, we know these butyl-rubber vacuum lines will deteriorate....if in doubt disassemble and replace the chewing gum and coal tar lines with proper silicone rubber ones~
http://www.partsgeek.com/fyn6gcq-ford-f250-super-duty-blower-motor- resistor.html? utm_source=nextag&utm_medium=pf&utm_content=wc&utm_campaign=Par tsGeek+Nextag&fp=pp&utm_term=Ford
okay what you need to check is the "blend door" for the defroster circuit~ https://www.google.com/search?q=2002+Ford+F- 250&rlz=1C1CHFX_enUS571US571&oq=2002+Ford+F- 250&aqs=chrome..69i57j69i59&sourceid=chrome&espv=210&es_sm=93 &ie=UTF-8#q=2002+Ford+F- 250+defrost+diverter&tbm=shop&spd=10071776584075119709
Ford diesels do not produce enough vacuum to run the heater controls. There is an electric control unit on the right inner fender that produces the vacuum for these. It is bad. Replace the thermostat for heat. It is stuck open. Blower motor resistor is bad for the speeds. Just follow the wires back from the blower motor to it.
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