If your Honda Civic has a bad alternator, you need to replace it, or it will quickly drain the car battery. Reaching the battery to disconnect it can be a bit challenging. The alternator in the Civic is linked to the air conditioning compressor and the power steering pump, so you need to get those out of the way. Also, you need to replace it with the exact same type of alternator your model originally had.
Disconnect the cable from the Civic's negative battery terminal. Raise the front end of the car on jack stands, and remove the left side wheel.
Remove the belt for the power steering pump by loosening its mounting bolt nut and locknut, and slipping the belt off the pulleys. Remove the pump by disconnecting the fluid hoses at the pump (clamping the hoses shut to prevent fluid loss), removing the pump adjusting bolt and the mounting nuts/bolts.
Disconnect the harness clip securing the harness to the alternator by pressing its lock button. Remove the nut attaching the output cable to the alternator's backside. Disconnect the electrical connector from the alternator, and set aside the output cable.
Remove the drive belt for the alternator and air conditioning compressor by loosening the alternator's upper and lower mounting bolts, and the adjuster bracket lock bolt, then slipping the belt off its pulleys.
Detach the alternator from its lower mounting bolt (the one between the alternator and compressor) by removing the bracket's lock bolt and adjusting bolt. Remove the upper mounting bolt, and remove the alternator.
Make sure you have a replacement alternator that is exactly like the old one, with the same ID numbers and the terminals being identical in size, number and location. If the new alternator has no pulley, you'll need to swap the pulley from the old one; many auto parts stores will do this for you.
Install the new alternator in the car, tightening first the upper bolt, and then the bolts on the lower bracket.
Replace all other components in reverse order of removal, then reconnect the negative battery cable.
