2018 PETERBILT 579 Electrical System Problems

This vehicle about 6-8 weeks ago started throwing codes for all systems above (over 100 codes). This issue affected all systems of the vehicle including but not limited to the speed and braking of the vehicle, plus the fuel system and adaptive driving systems. We took it to the dealer Performance Peterbilt in Tifton, GA. They cleared the codes and said they resolved it by replacing a NOX sensor. We left the repair shop and within 50-100 miles the exact same issue started up again. We took it back to the same shop, they worked with Paccar and determined it needed a new ECM (Computer), this was changed out and still did not resolve issue. They then changed out the main wire harness. This resolved some issues but not all issues. Now the repair dealer is stating it needs a dash wire harness. This vehicle has relatively low miles 500K...

On 8/10/2024 our sleeper berth hvac fans abruptly quit working. After checking fuses we noticed the fan control switch was hot. After removing the panel that the switch is held in we noticed the HVAC Fan Control switch (Part# 599-5000) was charred, upon removing the switch from the plug we observed the actual plug is melted, and one of the wires on the wire harness has charring of the plastic insulation. This could have very well caught fire. I am going to have to replace the wiring harness as re-pining the plug will not solve the issue of the wire being burned and the insulation being charred. There was no warning lamps, occasionally the fan would turn off then resume.

TL* THE CONTACT OWNS A 2018 PETERBILT 579. THE CONTACT STATED THAT WHILE THE DRIVER WAS DRIVING, THE REAR BRAKES AND TURN SIGNALS FAILED TO FUNCTION. THE NEXT DAY THE RUNNING LIGHTS ON THE DRIVERS SIDE FAILED, THE PASSENGER SIDE OF THE TURN SIGNAL AND BRAKE ALSO FAILED TO FUNCTION. THE CONTACT STATED THAT THE MAIN ELECTRICAL HARNESS COMING OUT OF THE MAIN COMPUTER AND RUNNING THE ENTIRE SPAN UNDERNEATH THE CAB HAD LITTLE TO NO PROTECTIVE SHEATHING/ CORD WRAP/ ALUMINUM WRAP PROTECTING THE WIRES. THE HARNESS WAS ROUTED THROUGH A U-BOLT TYPE FLANGE AS WELL AS HANGS NEAR SEVERAL METAL PARTS THAT, WHILE IN MOTION, RUB AGAINST THE WIRE CAUSING THEM TO FRAY. AS A RESULT, SEVERAL ITEMS BEGAN TO SHORT OUT AND ALSO CAUSED NUMEROUS WIRES TO HEAT UP AND MELT. IT WAS DISCOVERED THAT THE RUNNING LIGHT BRAKE LIGHTS INTERN SIGNALS BEGAN TO FAIL. THE HARNESS COULD...

THE MAIN ELECTRICAL HARNESS COMING OUT OF THE MAIN COMPUTER AND RUNNING THE ENTIRE SPAN UNDERNEATH THE CAB HAD LITTLE TO NO PROTECTIVE SHEATHING/CORD WRAP/ALUMINUM WRAP PROTECTING THE WIRES. THE HARNESS IS ROUTED THROUGH A U-BOLT TYPE FLANGE AS WELL AS HANGS NEAR SEVERAL METAL PARTS THAT, WHILE IN MOTION, RUB AGAINST THE WIRES CAUSING THEM TO FRAY. THIS IN TURN CAUSED SEVERAL ITEMS TO BEGIN TO SHORT OUT AND ALSO CAUSED NUMEROUS WIRES TO HEAT UP AND MELT. IT WAS DISCOVERED WHEN THE DRIVERS SIDE HEADLIGHT FAILED AND THE SAME SIDE RUNNING LIGHTS CAME ON AND STAYED ON. THIS ALSO CAUSED THE WASHER FLUID PUMP TO TURN ON AND RUN CONSTANTLY, HEATING IT TO THE POINT OF SCALDING TO THE TOUCH. NOT HAVING ANY TYPE OF PROTECTIVE WRAP AROUND THE HARNESS COULD CAUSE FRAYING AND A POTENTIAL FIRE AS WELL AS SEVERAL MODULES TO FAIL AS IT DID IN...