200AMP fuse in battery box ???

Sounds like it makes your truck start...or not start

 

Chase the wire and see where it goes. You may also be wiggling the harness below.

 

@Goodysnap

 

That fuse holder looks aftermarket to me. Any mega fuse holders privided by Paccar would be mounted to the inside of the battery box. As others suggested, trace the cables to find what the fuse feeds. My guess is most likely inverter power wired in post truck delivery.

I would suggest doing a complete battery service, clean and service the cables. When you move the fuse holders your moving or making a bad connection somewhere. Also make sure you battery holdowns are in place and tight.

 

One of the battery cables going to that fuse is not in very good shape .. I can see it is full of corrosion.. in the picture ..

 

And be very careful when your working with the battery cables .

disconnect the negative cable first .

you accidental drop a wrench across the Pos and neg terminals or put a wrench on the pos and turn it and touch something metal and it ain’t gonna be pretty .

I’ve done trail side welding with two car batteries , jumper cables and a coat hanger . And it’s works pretty well .

 

Inverter fuse like Goodysnap said. Fuse is good for a 2000w inverter. Chances are that’s what you have is a 2000w inverter?

 

My truck had a similar fuse and holder, and it was responsible for powering the whole truck. Mine ended up getting weakened due to bad roads and not being secured, and eventually gave out. Replace it with something that is secure and isn't going to move around much. I couldn't get the nuts off on the old one, so I had to cut it and crimp on new connectors as well.

If it goes out while driving, you lose all power and lights, so hopefully there's somewhere safe to coast to immediately. It's bad working on the driver's side of the truck with traffic so close. We had triangles out, and even if we had hazard lights working, I'm guessing people still wouldn't move over for whatever reason.

Before this happened, the truck was showing lower than normal voltage on the dash. Alternator was putting out around 14 volts, battery was also receiving 14 volts. The dash displayed between 12.5-13.5 intermittently.

 

There’s a small magnetic battery powered strobe light called “guardian Angel “ . About $100, that’s very bright , even in full sunlight . Available in many colors . I have the Amber one .

I carry two of them ,
It’s a nice addition to the triangles and if you lose all power , you at least still have some kind of blinky light .