The instructions were not adequate to ensure proper press fitting of the serration parts of the pulley and bosses of the air conditioner compressor, and therefore, the pulley's pitch circle may become distorted and the welded part may come off, in which case the pulley would fall into its slipping state. If this continues, the auxiliary engine-belt may come off, so the generator would stop functioning, and in the worst case, the engine would stop and fail to restart.