So normally when you want to test your fuses, you set the car to on and put the tester clip to ground then put the tester's lead on the fuse. if it lights up then the fuse is working. Well, even when I remove the car key, the tester light still comes on. This seems to indicate a short somewhere. Also when I measure the current with a multimeter by disconnecting the negative lead on the battery, it shows about .8A with the car off. Also, when I reconnect the negative lead to the battery, sometimes it activates the car like it would drive the radiator fan for a second or some other electrical parts. There's also loud clicking noise like the starter is engaging but only for a second. Does anyone know what's going on?
That just means that particular circuit is an always on circuit and not switched by the ignition.
When you reconnect the battery lead the computer is probably doing a power on test and as such some relays are being activated such as testing the fan etc.