I have a 2000 Honda CR-V. Some time back the Air Conditioning abruptly failed. Moreover, the ventilation fan only comes on if the fan knob is turned all the way to max. Its speed cannot be adjusted to intermediate values. Even when the fan does come on, the air conditioning does not. The heating works fine though. I do have a service manual for the CRV and would like to try to fix it myself. Any ideas on where to start? Thanks -M