Hello everyone, I am borrowing my wife's godmother's 2000 Civic. While we were out a few weeks ago, we were using the AC and went into a store. We came out and turned it on and nothing happened. The AC green light will light up but nothing blows out of the vents. I tried the heat and same thing. I can hear the doors closing while adjusting the hot/cold mix and when turning the vent/defrost controls as well. I checked the fuses and nothing was blown. I'm not sure where to go from there. I was thinking blower motor since heat and AC don't blow but I'm not sure. I'm automobile savvy but not when it comes to AC systems and definitely not Hondas. I'm used to working on carbureted American vehicles. I've never owned an import so I'm not sure what's different (if anything) about them. I own a multimeter but I'm not sure how to go about using it to diagnose relays, etc.

If anyone could help me out, it would be greatly appreciated. I've fixed my own car and would like to return her car but I don't want to without it being in the condition it was in when I received it.

Thanks,
Arthur


NOTE: Forgot to add that when the car is not running and I turn the AC on, the radiator fans will run for about five seconds then shut off. I also just went out and checked that the compressor clutch is not engaging when the AC is on.

 

Usually the problem with the interior fan is the power transistor. Find the fan motor under the dash on the far right side. It has a 2 wire plug with fairly heavy wires. For this test, leave the plug plugged in. Turn the key on and set the fan switch on high. Probe in the plug to measure the voltage from each wire to ground. If there is 12 volts on both wires, replace the power transistor. If there is 12 volts on one wire and near zero on the other, the motor is bad. Zero on both wires, check the fuse and relay (in the fuse box near the battery).

The refrigeration system should start working again once it has some airflow from the fan.

 

It's been a while since you posted mk378 but just wanted to come back and confirm that the power transistor was indeed bad. I bought one off of ebay and now I can give the car back to her. Very easy to replace and I thank you for taking the time to point me in the right direction!