Diagnostic Flowcharts: Starting System Troubleshooting

Well, I have been having issues with the starting of my coach. It is a 2001 U320 with the Cummins ISM engine. It would start, but the issue was after turning the key the whole starter would start to crank and then stop for a second and then spin right up and the engine would fire up.

The issue was that the gauges would then do the self-test again indicating that the ECM had lost voltage enough to think that it was a new start.

I was at Cummins and we had replaced the starter already last year and the batteries. The new started made it start much easier but there was still that little hesitation after turning the key. I talked with Ben (ryderpoo) on here and he had the same issue.

He had figured out that if he ran a second set of cables from the battery directly to the starter it would solve his problem. He did it and it solved it so I showed the shop foreman at Cummins the picture and they talked it over and said that would work.

Of course, the batteries I had did not have the side posts or even enough juice to work so I had to have them all replaced again. The new set up spins the engine great and there is no hesitation and it starts right up without the boost switch faster than it did with it.

There is a junction box that takes the battery leads and splits it to the isolator and then to the starter and it looks like it goes one other place but it was hard to see. Direct wiring of the battery to the starter and all the grounds had been cleaned and improved to make a better connection to the last visit. I think we have this issue licked now and wanted to share it with the group. I know that many of us hate to try to start the engines up in the cold weather but this setup works much better. This will work much better in the cold weather as well. John Sichenze 2001 U320 42′