So we have a 2002 ford zx2 with about 140k miles on it currently. For the last 6,000 miles the heater stopped working. Since we're tired of being ice cubes we tried to trouble shoot the problem starting with the blower motor itself. We ended up just replacing it because the old one was just in bad shape in general. The resistor was replaced and so was the relay. We also ended up replacing the switch (we did all of this because it wouldn't work after each fix, yes I know terrible trouble shooting! lol). Oh we also replaced the fuse too Anyways kind of outa ideas at this point and lost.. The wires themselves looked in pretty good condition and we even cleaned them properly just in case. The new blower motor was tested and works itself as well.