You will need to get a repair manual for this because you will be pulling the dash and the complete a/c-heating box out, very complicated......................
No.
Unscrew the one bolt that holds it on.
Counterclockwise to remove, clockwise to tighten.
No
They are the same from 1994 to 2002.
No the 1999 and 2002 1500's are different body styles.
It is possible that your radiator is partially plugged or the heater core is leaking coolant or the thermostat is the wrong temperature. Sorry for so many scenarios, but I have seen all of these.
The valves on a 1999 Dodge Ram 5.2L are not adjustable.
You will have to remove the whole instrument panel. Then lower or remove steering column. Then disassemble heater case. Best taken to a dealer due to possible steering column issues, not impossible though. is it the same as a 1998 heater core replacement
I have never heard of a mixer on a dodge truck.
No
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