Freightliner Can't Fix My problem

Did they show you or give you the old harness?

 

I bet you've got a loose/broken wire. Try and wiggle all the wires and connections you can reach safely with the truck idling. See if wiggling a specific harness or wire will make it stumble or stall.

 

I'd hazard a guess it's one of the main power feeds/earths, sure nothing is earthing out on a block or frame anywhere, ecm/fusebox mounts are loose? To me that's vibration related. Can you run a multimeter off your alt and then batteries and have someone monitor it in cab while running down the road, could be a power spike or drop out that's causing it, I've had that issue on other heavy equipment before on rough terrain. When the shop tested it, assume truck was bobtail? Could be trailer wiring related as only faults when you have a load on?

 

Not sure if century's use the same setup, but we had a crapcadia doing this, it ended up being the load controller which gets signal from disconnect switch. New controller, no problems.

 

I could not find any mention of checking for cracked fuses in the PDM. In addition, does your truck have a PNDB? If so, those contacts can go bad as well. Because the way the cluster turns off and right back on signifies the symptom of losing a VBAT to the ECM. Very characteristic as shown in your video--which is why the cluster goes off and snaps back to place. Another thing to check is the female pins on the fuses themselves. Do a pin drag test on all VBAT, IGN, GND, etc pins...are they tight? Yes? No? Figure out all the VBATS, GND, IGN to the ECM, and do a load test. What's the voltage drop?

A competent dealer would be able to diagnose this problem and find a cause from doing the above mentioned tests. Trying to slam dunk a power problem with a new wire-harness will not cover all circuits through their entirety.

As for other questions asked in this post, the oil pressure will remain as long as the cranks is turning. The engine fan comes on just like a normal start up would because the air solenoid to the fan cycles power.

 

When I mentioned the oil gauge. I was thinking that the sending unit was sending a bad signal to the ecm. Telling the motor to shut down. (no oil pressure) When the ecm goes nutz. Is the oil gauge needle bouncing around. But the fan circulated like the Air Conditioning system was coming on. Just for S\G maybe check the key switch connections behind the dash. (maybe a bad key switch) just my $0.02 .

 

I worked for Freightliner. I'm pretty sure I know your issue. The century and Columbia models had issues with the series 60's. I have personally fixed the issue you are experiencing. You are losing the j1587 communication between the engine ECM and the cluster. I've found that when tracing the OEM harness off the engine ECM, which is where the j1587 wiring is ran, they have been rubbed through either by the p-clip about a foot away or the loom has rubbed through the wiring. It was pretty common. My advice is for you to remove the p clip from the left side of the block and open the wiring loom. You should find a pair of twisted orange and green wires. Hopefully you find the bad spot in the wires but I've just used heat shrink butt connectors to repair it trying to keep the twisting there as best as you can. Hope this helps.

 

Replace the oil temp sensor and oil pressure sensor......