Principles of Operation
PRINCIPLES OF OPERATIONWhen the key is in the ON position, voltage is supplied to the upfitter relay control circuit. The upfitter relay closes and voltage is supplied to the upfitter relay box. The upfitter switch assembly receives voltage through the upfitter relay box fuse 701 (5 A) and then distributes voltage to the 4 circuit control switches. When a control switch is closed it supplies voltage to 1 of the 4 upfitter relays in the upfitter relay box, closing that relay. Voltage is supplied to the switched side of the upfitter relay circuits from the central junction box (CJB). When the relay closes, voltage is supplied through the relay to the output circuits (blunt cut ends) located under the LH side of the instrument panel. The output circuits (blunt cut ends) supply voltage to the installed accessories connected to the upfitter relay box.