Originally Posted by pizzaguy

You have GOT to get under there and see what the situation is. I think you have two issues here, from the water intrusion.

1) It is likely that the 'blower motor resistor' is damaged, easy, cheap fix. I suspect the blower motor is also damaged. I'd bet you will be changing both.

2) I think it is likely the amp for the radio is water damaged. You must pull up the carpet in the passenger footwell, then remove the cover plate over the amplifier. It will be easy to yank out the connectors from the amp and see if you have corrosion on the connector pins. If you do, it's time for a new amp and new wiring. The easiest and least expensive method is to go with an aftermarket JVC/Kenwood/Clarion/etc. amp.. While doing this, you could run four more wires from the AM/FM head (if it is an aftermarket head) and provide yourself true four channel sound. This way, you do not waste months chasing OEM connectors and wiring harness. Wiring up a new head unit and amp, using the existing speakers and speaker wire runs, is not all the difficult compared to trying to restore the awful, factory two channel system.