No Defroster

1994 4.0. I just replaced the blower and resistor, and gave the climate control switches a good scrub. Now every mode of climate control appears to work, except for the defroster. On defrost, the blower just stops running. Any ideas what could be wrong?

And yes, my AC is probably shot, but I shouldn't really need it.

When you say you gave the climate control switches a scrub maybe you disarmed the defrost feature, which supplies power to the blower. See center switch function on the last schematic.

These schematics should encompass the '94.

Vacuum system:



Blower system: