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Onan MDKD Repairs


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  #11  
Old 03-10-2016, 09:09:50 PM
KPack KPack is offline
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Default Re: Onan MDKD Repairs

Quote:
Originally Posted by akirkland View Post
You need service manual 981-0502,it has wiring diagrams and start stop seguence explanation.
That service manual is here.
http://www.twinslan.net/~n0nas/manuals/onan/
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  #12  
Old 03-10-2016, 09:27:20 PM
akirkland akirkland is offline
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Default Re: Onan MDKD Repairs

A number of things must happen when this generator starts in order to have 12 volts on this wire to the hold in coil on the fuel solenoid. Oil pressure, ac output, relays must energize, as mentioned in an earlier post a safety could be giving you trouble. The manual will help walk you thru it. It also shows where some of the safeties are located and what they look like.
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  #13  
Old 03-10-2016, 09:49:53 PM
Viking66 Viking66 is offline
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Default Re: Onan MDKD Repairs

Thanks.

I do have the manual, and the wiring diagram. It does put out AC Power, I checked that when I first got it running.

Wired the Control Power Latch together to see if it may be the cause but it wasn't.

I will check the Oil Pressure Sensor tomorrow and see what happens then. I switched out the K14 Relay and can feel it click, so that shouldn't be the issue.

I will keep hammering away.
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  #14  
Old 03-10-2016, 11:18:48 PM
akirkland akirkland is offline
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Default Re: Onan MDKD Repairs

It would appear that K12 is not energizing. Check hi temp shutdown switch, must be open. Oil pressure shutdown switch is normally closed, open when running. Overspeed switch open. High temp exhaust switch open. Make sure cb12 breaker is not popped out.
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  #15  
Old 03-11-2016, 10:24:33 AM
akirkland akirkland is offline
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Default Re: Onan MDKD Repairs

Verify that wires are correct as per the wiring diagram. If your safety shutdowns are working properly, and you have a new K14 relay that works, which it apparently does since fuel solenoid pulls in during start cycle. Check Ac terminals on A11 board, must be at least 90 volts ac when running. You have already jumpered S6 oil pressure switch, and you have found no bad fuses or tripped CB12 breaker, it sounds like you may have a defective A11 control board
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  #16  
Old 12-06-2017, 07:34:23 PM
Viking66 Viking66 is offline
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Default Re: Onan MDKD Repairs

Been a few years since I opened this thread, but I think my DJE at my Camp may be toast...Not putting out AC, so I decided to look at this Genset that is currently in my Garage.

I am thinking that the High Coolant Temp Switch may be bad.

I went ahead and pulled it from the Genset and cleaned it up. As it sat it was open. I got some water boiling and put the end that goes near the Thermostat into the water for a good 2 minutes and it was still open.

Am I testing this correctly?

Thanks as always!!!
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  #17  
Old 12-06-2017, 09:41:37 PM
nothingbutdarts nothingbutdarts is offline
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Default Re: Onan MDKD Repairs

I'm not sure but, I think it's more in the 300 degree range.
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  #18  
Old 12-07-2017, 07:25:39 AM
Viking66 Viking66 is offline
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Default Re: Onan MDKD Repairs

Nothingbutdarts...you are correct that is it higher than boiling point. I looked over the schematic and it shows as a NO type switch, so instead of in the water I stuck it in the flame on my stove and sure enough it closed.

I have the Oil Pressure Switch grounded since it is a NC Switch.

I am now thinking it may be the A11 Control Board that is giving me trouble. Not sure of any way to check it besides swapping it out, but that is either a $100.00 dollar adventure from ebay, or a $159.00 adventure from Flight Systems.

Thanks for any and all advice on this matter!!
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Old 12-07-2017, 08:35:08 PM
zuhnc zuhnc is offline
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Default Re: Onan MDKD Repairs

If your oil pressure switch is "closed" ( or continuity) with NO oil pressure, then it must be "open" (NO continuity) with the engine running. If the wire is grounded with the engine running, the engine will SHUT DOWN. I.e, with NO oil pressure the switch is closed, grounding the safety circuit. Test by completely removing the wire from the switch and taping it. Check the switch when the engine is stopped; should have continuity (NC, as you stated), When the engine is running, the switch should be OPEN or no continuity. If it does not go open, then the switch is faulty, or you have no oil pressure. Most schematics and wiring diagrams show components in the de-energized position; no power applied, including any pressure or temperature signal. Any exceptions will be noted on the diagram. zuhnc
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  #20  
Old 12-09-2017, 07:24:16 AM
Viking66 Viking66 is offline
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Default Re: Onan MDKD Repairs

I checked the Oil Pressure Switch, the High Temp Switch and the Control Power Latch Switch 6 and all read out good on my Multi meter.

I am going to put things back together and see if it will stay started.

If not, I will pull the wires from the NO type switches and tape them just as a double check to see if they are actually working.

My main goal for this is to convert it from a Marine to a Land version. I think my DJE at my Swamp Camp has bit the dust (No AC output) and i will be needing another unit out there.

I found out that the Exhaust Manifold is $152.00 Ughhhhh I think I can use the one from the Marine version, just no coolant going through it and an adapter to install a regular style exhaust.

Just trying to work things out
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