Hvytrkmech

As most of you know poor electrical grounds cause all kinds of electrical problems. Some easy to diagnose and some very difficult. The following pictures are of a 0000 ga. main ground cable for a class 8 tractor. This tractor is one of the few customers that we have that I will actually do repairs for. Truck was towed from a reputable dealership to our shop this past Friday. truck was at the dealer multiple times for extended crank to start, erratic start, a plethora of drivability concerns, and finally a no start due to no crank.

Dealer installed the following items on different visits.

4 new batteries
All new battery jumper cables.
New + cable from batteries to starter
New - cable to new grounding stud on frame.
Re-manned starter
New ecm
Another re-manned starter.

There are other items over the last few months, but you get the idea.

So I dive into this thing Friday with the worst possible thoughts going through my mind. After about 1.5 hrs of smashing my skull I decide to go back to the basics. I start checking grounds and this is what I find. Ecm ground, cab to body ground, engine to frame ground all fried. So I think what would cause all these grounds to self destruct, then I had an epiphany. Something was searching for a major ground and found it through all these other grounds causing them to overheat and melt. So lets check the main ground from the starter to the frame, I had to remove a fuel heater/water/air separator unit to access the ground lug. I remove said unit and locate the ground lug, it looks ok but I want to remove it to inspect the cable and ends and to make sure the ground lug was not rusting off the frame. Once I pulled the nut holding the cable I pulled the cable off the stud, the cable instantly broke in two in my hand. When you look at the insulating jacket on the cable there were absolutely no visible signs of bulging or tears that would have lead to this failure. The pictures speak for themselves. Some new cables and the truck starts and runs like a champ.

Just passing along some info on something I have not run across in this manner before. Hope it helps someone.

madhat

Good post, buddy. Start with the cheep/simple stuff.

mishkaya

It has been my experience that a lot of the driveability issues on the more recent vehicles are frequently due to ground problems....

pind

Tim,

Good find there man. Ground effect widowmaker at its finest.

Don't you love it when its that "simple"?

Hvytrkmech

Exactly.

My point exactly, however after 26 years I have never run across a failed 0000 ga. cable that showed absolutely no physical signs of failure. Example; green corrosion oozing from under the swedged heat shrinked ends, corroded, erroded ends, bulging insulation, or chaffed exposed insulation allowing for expedited failure. But you knew that already.

, perfect vernacular for that! I had run my hand along the length of the cable several times and did not find anything that would cause suspicion. Never had a cable like that break like glass before. I bet you see that a lot in the environments you work in.

Fordzilla

Now you have...And in the 35 years I spent mechanicing, the one consistent factor was that I learned something new every day......Ben

Hvytrkmech

No doubt about it.