One problem related to wiring has been reported for the 2004 Chevrolet Silverado 2500. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Chevrolet Silverado 2500 based on all problems reported for the 2004 Silverado 2500.
Heater fan wiring harness overheats burns thru at connector between resistor and harness. Several wires in connector -the lead for full power to motor ( high speed setting) is supplied by 40 amp fuse. Wire is approx 16 gage with terminal connections subjected to long duty cycle with high amp load. Wire harness overheated causing fire in vehicle in oct 2005 ( 7,657 miles). Repaired under warranty. Repeat failure in Aug 2010 ( 24,615 miles) on 2nd failure dealer stated happens all the time so he had parts dept keep ample supply of resistors and harnesses in inventory. Refused to repair under warranty. 2nd repair done by vehicle owner. Part numbers used in 1st repair by dealership were; connector 88953358 and resistor 89018596. 2nd repair by vehicle owner used delco parts #s - connector del15-81086, and resistor del pt2485. On 2nd repeat failure the new connector appeared more robust in design in area of contact patch between harness and resistor. Terminal interface seemed improved.