Cat Electrical 621F and 623F Wheel Tractor-Scraper Electrical System Schematic Manual - PDF DOWNLOAD 621F Tractor: 4SK1-UP 8PL1-UP 623F Tractor: 6BK1-UP 621F Scraper: 5JK1-UP 9NL1-UP 623F Scraper: 5SG480-UP
