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My Onan 7500 quiet diesel generator was acting up, gave the…

Customer Question
Hello, my Onan 7500...

Hello, my Onan 7500 quiet diesel generator was acting up, gave the fault code 3-3-6 I think. Yesterday we replaced the fuel filter and it fired right up and purred right along. Tested it for about 20 minutes after warm up on two A/c heat pumps in my coach and was working great. Shut it down, and drove for 10 hours not using it. Pulled in last night and I’m getting fault 3-2-6, I can’t even find that code listed anywhere! Anyway, any advice is appreciated. Thank you. Brian-

Mechanic's Assistant: What's the make and model of the generator? And can you guesstimate how old it is?

This coach is a 2000 Monaco. I’ll get the model, just a sec

Mechanic's Assistant: Do you plan on doing the work yourself?

That depends, you have an idea? It’s unfortunate it’s Sunday, freezing here, and I’m headed to oregon :-(

Mechanic's Assistant: Anything else we should know to help you best?

OK model number is ***** HDKAJ11451D

Submitted: 4 months ago.Category: Small Engine
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Customer reply replied 4 months ago
I literally just bought this coach so I’m not familiar with it’s maintanence history. Also, it has 2372 hours on it currently. Thanks. Brian-
Answered in 1 hour by:
3/18/2018
Technician: Hank F., Technician replied 4 months ago
Hank F.
Hank F., Technician
Category: Small Engine
Satisfied Customers: 15,979
Experience: Certified on Onan and Generac generators
Verified
Hello, my name is ***** ***** I am going to assist you with this.
What is the serial number of the genset?
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Customer reply replied 4 months ago
Let me get that for you give me just a second please, may take me a couple of minutes is that OK?
Customer reply replied 4 months ago
Ok Hank, I appologize for delay, I just got off the pass. The serial number is:
F990 933125, thank you.
Customer reply replied 4 months ago
I’m not going to be able to tear into it today, can you explain to me, or is a walkthrough better? If so, can we schedule time for tomorrow to walk through? What is your opinion of my problem Hank? Thanks, Brian-
Technician: Hank F., Technician replied 4 months ago

Sorry, I was at work.

I work 2 day jobs, and normally help on Just Answer in the evenings.

If things are running good at work, I am often able to field a couple of questions during break. But right after I responded to you, things went to pot, and I didn't get a chance to get back on.

Code 26 on your unit is Engine Speed Below Target Fault. This is a very complicated code. There are some things you can do and check, but there are many things you will not be able to do, unless you are a qualified diesel mechanic and have the proper tools.

Try this first:

Press and hold the STOP/PRIME button for about a minute.

Then try to start the genset.

Will it crank?

Will it start?

If it starts, let it run for at least 30 or 45 minutes.

Does it stay running that long?

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