I have a 2000 Caravan that refuses to blow air through the heater or A/C. I have checked the fuses, exchanged the 1" cubed relay under the hood with another that worked in another position, exchanged the switch with another from another van, as well as the coil resistor that pokes into the air plenum from the firewall side. I hot wired the motor, and it runs on high. I don’t see any broken wires, but granted they are buried in bundles.
What else is there to check?
Do you get power to the motor with the switch on?
Blower motor resistor block may need replacing. Check next to the blower motor of the block (Below/behind the glove box)
The OP clearly said they had replaced the blower resistor.
I would next go to the fan switch itself.
No
I have two of these vans. I took the switch out of the other one, so the problem isn’t there.
Power is applied to the motor through the blower relay and fuse 107 in the panel under the hood. Verify power is getting to the dark blue wire tied to the relay when the blower switch is on along with the ignition. If you have power there then check see if the power is getting to the motor lead. The switch and resistors are on the ground side of the load. If you have voltage at the motor you should be able to ground the blk/tan wire going to the motor and turn on the blower. That will verify that portion on the circuit. You will then need to see if voltage is getting to the switch on the same blk/tan lead. If that is ok then also verify that the blk wire going to the switch is getting to ground.