Hard to Diagnose Problem Solved

[MYTraveler]

May I ask what type and year your boat is sir?

Mikelson Nomad' commissioned in 2009. Problem is not with original construction as much as Cummings design of QSM 11' and Cole Hersee switch.

 

[BevinB]

Mikelson Nomad' commissioned in 2009. Problem is not with original construction as much as Cummings design of QSM 11' and Cole Hersee switch.

Thanks. I have QSC’s of the same year with the same stop buttons so thanks for sharing your experience with us.

I may get the switches replaced as a precaution.

Magnificent boat btw.

 

[twistedtree]

Thank you, that is reassuring, especially coming from you. And I figured it is useful information in case anyone else gets stuck with something even similar. What I really needed was a pinout.

I had a pair of Cummins QSC 8.3 in a former boat, and I was able to find a long and dense wiring manual. As I recall it showed all the harnesses, where all the options connect, different configurations, etc. And I think it was down to the pin numbers. I might still have it and can send to you. I don't know if it's applicable to the QSM, but at least it might show you want to look for in terms of documentation.

 

[MYTraveler]

I had a pair of Cummins QSC 8.3 in a former boat, and I was able to find a long and dense wiring manual. As I recall it showed all the harnesses, where all the options connect, different configurations, etc. And I think it was down to the pin numbers. I might still have it and can send to you. I don't know if it's applicable to the QSM, but at least it might show you want to look for in terms of documentation.

That would be great. PM sent. Thank you! -Rick

 

[DDW]

Does the stop button shut power to the ECM, or just provide a signal telling the ECM to shut down?

If there are multiple stations, then the normally closed, momentary open is the easy way to produce the logic (wired AND function). Similar to the way machine tool E-Stop chains are wired.

With a wiring diagram, it would have been easy to notice and check. If this is the way QSMs are commonly set up, I'd be a little disappointed in the expertise of the Cummins technician that looked at it.

 

[MYTraveler]

Does the stop button shut power to the ECM, or just provide a signal telling the ECM to shut down?

If there are multiple stations, then the normally closed, momentary open is the easy way to produce the logic (wired AND function). Similar to the way machine tool E-Stop chains are wired.

With a wiring diagram, it would have been easy to notice and check. If this is the way QSMs are commonly set up, I'd be a little disappointed in the expertise of the Cummins technician that looked at it.

I would think that normally open could be just as easy with multiple stations -- perhaps easier -- just power a pin monitored by the ECM. The normally open approach requires the use of two pins and prevents the diagnostic approach (suggested above) of disconnecting everything any adding stuff back until the offending item is found.

I did ask for wiring diagrams and was told every boat is different. Even so, a generic diagram should still be easy to provide. A pinout would have been sufficient, but I couldn't get my hands on that either. Pretty frustrating.