No electrical power to genset for startup

[lout]

Hi everyone, I have a Onan 8kw MDKD genset that started up and ran just fine untill I had a water pump replaced by a marine service dept. The raw water pump was simply not pulling prime anymore and had reduced water flow so after new Impeller and other checks a new pump was installed.
I have just recieved an email that it dosent start and that maybe it is a bad starter or start stop switch or various other magic items and that the search for repair can begin at 119.00 an hour.
I went to the boat to find that there was no power to the genset circuit board and no electrical power to the genset from the salon remote start station either.
So i am now asking some of the most informed people on the planet for things to look for. The battery cables are connected and it appears that the circut fuse on front panel is not triped. What to do now?
No power in panhandle.

 

[Arthurc]

Do you have a multimeter? Can you identify each component involved and test one at a time? I had this once when I took mine out for a sea trial mid work being done, they had left a power switch off I didn’t even know existed.

 

[Comodave]

Sounds like you are not on the boat. Sounds silly, but I had that happen on my genset. I was ready to jump into troubleshooting when I realized the breaker on the genset had been flipped off. It is tight by that side when I get to the batteries and I must have brushed against it and turned it off. Maybe something like that if it was working before the impeller replacement. Maybe they accidentally turned off a switch or breaker.

 

[BruceK]

Hi everyone, I have a Onan 8kw MDKD genset that started up and ran just fine until I had a water pump replaced by a marine service dept. The raw water pump was simply not pulling prime anymore and had reduced water flow so after new Impeller and other checks a new pump was installed. ....
I went to the boat to find that there was no power to the genset circuit board and no electrical power to the genset from the salon remote start station either....

Working fine before the pump was replaced,but not afterwards? Not being big on "coincidence",I`d be looking for something changing during the repair job. Is the main switch for the genset set to "On"?

 

[lout]

Thanks everyone ! Some great thoughts I wish I had been able to be there on the boat during repair. I hate to chase someones work but I am not feeling the we can fix it for more story.

 

[caltexflanc]

Not uncommon for the tech to flip the power off before working on the unit to prevent accidental starts. Also not uncommon for things to break coincidentally.

As already mentioned this is where a multimeter is invaluable.

Also, you should send the old pump out for refurbishment so you have a spare. Depco Pump over in Clearwater does excellent work.

 

[Russell Clifton]

When I worked on my Westerbeke last week I turned off the battery switch that happened to be right above the generator. Could this be the case with yours?

 

[angus99]

When I worked on my Westerbeke last week I turned off the battery switch that happened to be right above the generator. Could this be the case with yours?

Ditto. I’m replacing the fuel solenoid on my Westerbeke and there is a remote battery switch, a conventional battery switch and a kill switch that must be aligned properly to power the unit. Also, sounds dumb to ask, but is the start battery charged? These are among the first thing to check.

 

[Comodave]

Agree,KISS principle. Always check the simple basics first. Good luck.

 

[lout]

Thanks for the tip

 

[wpc691]

Just check for 12V at B+ on the starter, if no voltage start looking for the aforementioned switches. If there’s standing 12V at the starter, check all the little white wires going to the various shutoff sensors (oil, exhaust temp, coolant temp). The water pump is a tight fit (like everything else), and one of those wires could easily get broken. The spade connectors on the back of the solenoid are easy to see, so I assume they would notice if one of those had gotten disconnected. I’m trying to troubleshoot an intermittent start problem with my 8.0 MDKD, so I feel your pain.

 

[STB]

You wrote that you aren't getting power at the controller. What does that mean? Does that mean the controller seems "dead"? Or does that mean you have measured 12V power going into the controller and it is 0V?

If no power is getting into the controller, the problem is likely not with the generator. It is likely, as folks have suggested, with a fuse or switch between it and the battery. Terminal block fuses can sometimes take people by surprise.

If the controller just seems dead, check the breakers on it, especially the "emergency stop switch", a.k.a. the "DC control" breaker.

On those units, the power for the remote panel, including start switch, comes from the controller on the genset, itself. So, if the controller isn't getting power, it won't, either.

In case it is of help, you can find the service manual, with schematics, here:
-- http://truckroadservice.com/barth_attachments/682105772_Onan_DKD_Service_Manual.pdf

The installation manual here:
-- https://www.scribd.com/document/408...ries-Marine-Diesel-Genset-Installation-Manual

And the operator's manual here:
-- http://www.grandbanksowners.com/member_manuals/Onan MDKC MDKD Operator\'s Manual.pdf

Good luck!

-Greg

 

[GGroves]

When we bought out boat, it came with a Westerbeke 8kw genset. During the initial survey, it had no electrical power to start. Checked all that everyone has mentioned. The problem turned out to be a 5 amp auto fuse controlling the start-up circuit. Replaced fuse and it started. See if you have an automotive fuse on the genset itself.
Cheerio
Gary

 

[wpc691]

When we bought out boat, it came with a Westerbeke 8kw genset. During the initial survey, it had no electrical power to start. Checked all that everyone has mentioned. The problem turned out to be a 5 amp auto fuse controlling the start-up circuit. Replaced fuse and it started. See if you have an automotive fuse on the genset itself.
Cheerio
Gary

Good catch - there is a fuse in the Onan start circuit.

 

[lout]

Update Sunday 8-19 after finally being able to get to the back side of the generator which took taking apart several partions etc you all know the drill, The mystery fuse was located and sure enough if was blown. After replacment i now have power to the unit. The preheat starts up the Genny turns over fires off and then the stop/start switch shuts itself off and the engine will not remain running.
Seems like i may have a bad fuel relay. At least I now have power to start checking the rest of the possibilities. Thank for all the tips about the fuses this one was down by starter on back side of generator. Hope this helps someone one day. If anyone has any comments on the latest . Feel free to reply.

 

[Comodave]

Is there any way to extend the leads to the inaccessible fuse and bring the fuse out to the front of the genset? Would make replacing it easier in the future.

 

[lout]

No electrical power to Gem at start up

Great idea on moving fuse around to front or back for anyone that has the reverse placement on your Onan generator. So for the final recap. If your generator has no power at all going to the control box find the fuse. There will be one eith under the control box in the engine compartment near starter keep looking you will find it and save yourself a lot of cash. Next if the gen fires off then will not stay started or starts and dies. Check the stop selenoid they are rather inexpensive and easy to replace yourself. The generator is now running great with that part replaced, a new fuse that has been rewired to the front where it can be located and changed. Thanks to all for the tips and advise along with the diagrams. Grateful to all