Dead control panel, motor runs

[kvstein]

I have a 5 y/o Yanmar 3jh5e. Yesterday the control panel went dead but the motor kept running. It shut down normally when back in the slip. Today it starts and stops. Checking other posts on the forum the engine is supposed to stop when the power goes out. The 3 amp fuse is intact. I noted a fuse on the purple/white line (panel power) but it is too yellow to see if it is blown. Another clue is that during the anchor drill the day before the panel began to blink and chirp. I am having difficulty getting a technician to call me back during this time of Covid. Any ideas would be much appreciated. Thanks.

[FPNC]

Check for a bad ground connection to the panel. When you have power but things are wonky, it is commonly a bad or disconnected ground wire.

[kvstein]

For the record the problem was a shorted switch on the control panel--the power button to be exact. It was the devil to figure out. Many thanks to Mastry Marine and to Tom at Sea Safer Marine of Largo, Florida.

[Jim Cate]

Checking other posts on the forum the engine is supposed to stop when the power goes out.

Unless your engine has an electric lift pump or is a common rail engine, the above isn't true. It will continue to run as long as it has fuel and air. One of the nice things about mechanically injected diesel engines!

Jim

[Wotname]

Originally Posted by kvstein

For the record the problem was a shorted switch on the control panel--the power button to be exact. It was the devil to figure out. Many thanks to Mastry Marine and to Tom at Sea Safer Marine of Largo, Florida.

Thanks for the update, glad to hear it was sorted. In case you haven't already done it before, now would be a good time to become familiar with the emergency stop procedure as outlined in the operation manual.

Anytime power (or a ground) is lost to the switch module, you can't operate the stop solenoid from the panel.

And FWIW, the 3 amp fuse in the panel only supplies power to the alarm lamp / tacho sections of the panel. There is no fuse to the switch module although I believe there is a fuse for each function inside the switch module.

[Wotname]

Originally Posted by Jim Cate

Unless your engine has an electric lift pump or is a common rail engine, the above isn't true. It will continue to run as long as it has fuel and air. One of the nice things about mechanically injected diesel engines!

Jim

A word of caution here Jim, while what you wrote is mainly true, it is not always true (at least not to all diesels).

I have seen some older mechanically injected truck engines that use a energised stop solenoid in the run position. Removal of current causes the solenoid to relax into the stop position - a failsafe design if you will.

This has caused me a headache before I cottoned on to what was going on - the engine just didn't want to start until someone kindly told me to check the stop solenoid circuit.

I dunno if such designs ever made it into the marine market but I reckon there will be one somewhere. IMO, such a failsafe design is bad idea on a boat but maybe a good idea on a truck (thinking of a master electrical kill switch in event of some accident).

[Jim Cate]

Originally Posted by Wotname

A word of caution here Jim, while what you wrote is mainly true, it is not always true (at least not to all diesels).

I have seen some older mechanically injected truck engines that use a energised stop solenoid in the run position. Removal of current causes the solenoid to relax into the stop position - a failsafe design if you will.

This has caused me a headache before I cottoned on to what was going on - the engine just didn't want to start until someone kindly told me to check the stop solenoid circuit.

I dunno if such designs ever made it into the marine market but I reckon there will be one somewhere. IMO, such a failsafe design is bad idea on a boat but maybe a good idea on a truck (thinking of a master electrical kill switch in event of some accident).

Well, I'll be... I didn't know about them, Wottie. Seems a damn fool way to run a navy, but then I never ran a navy myself!

On our engine, and all the other ones I've investigated on boats, the stop button energizes a solenoid which pulls the shut-off valve. Makes it easy to manually stop the engine whilst working on it below decks, away from the control panel.

thanks for the heads-up.

Jim