If you are replacing the alternator, take the old one with you when purchasing a replacement unit. Make sure the new/rebuilt unit looks identical to the old alternator. Look at the terminals - they should be the same in number, size and location as the terminals on the old alternator. Finally, look at the identification numbers - they will be stamped into the housing or printed on a tag attached to the housing. Make sure the numbers are the same on both alternators. Many new and remanufactured alternators do not have a pulley installed, so you may have to switch the pulley from the old unit to the new/rebuilt one. When buying an alternator, find out the shop's policy regarding pulleys; some shops will perform this service free of charge. Disconnect the cable from the negative terminal of the battery. Raise the front of the vehicle and place it securely on jackstands. On G35 Coupes, remove the front air spoiler. Remove the engine undercover. On G35 Coupes, remove the right engine undercover as well. On G35 Sedans, remove the stabilizer bar bushing retainers and allow the stabilizer bar to swing down, out of the way. On G35 Coupes and 3502 models, remove the radiator fan assembly. Remove the alternator/power steering pump/fan drivebelt. Disconnect the electrical connector from the alternator. Disconnect the electrical connector from the oil pressure switch and detach the switch harness clip from the lower alternator mounting bracket. Detach the battery cable harness clip from the alternator battery terminal remove the nut that secures the battery cable to the battery terminal and disconnect the battery cable from the B terminal. Remove the upper alternator mounting bolt. Remove the lower alternator mounting bolt and the mounting bracket bolt, remove the mounting bracket and remove the alternator. Installation is the reverse of removal.