[jorma]

I'm a newbie here and I'm having a real hard time figuring out what's wrong with my generator.  The typical "it starts fine on the start switch, but won't stay running?  I've tried to read all the threads I've found on here for the last 2 days and I've learned a lot. 
Here's my situation.  Then genset engine starts and runs on the start switch, but when I let go it stops.  I can manually hold the fuel stop solenoid forward and it keeps running and shows output on the on the 110v. meters inside the coach.  There is nothing showing up on the 220v. meters.  The cooling fan does not kick on.  I removed the solenoid to see if I could test it and it has 3 wires coming out of it, but only 2 are in the plug.  The third wire is separate and was not hooked up to anything.  It appears somebody has at some time tried to do some "backyard engineering" and has added some wiring and a relay in the wiring going to the plug.  Oh yeah, the generator is a Martin 17.5 unit with a Yanmar engine 4TN84TE.  The wires coming out of the solenoid are: 1 white, 1 black and the one not hooked to anything is red/blue.  I don't see how it could operate 2 functions with only 2 wires hooked up.  I thought it needed a "pull coil" and a "hold" coil.  I just bought this unit and have no knowledge if the generator has ever worked in this configuration.  The previous owner is deceased and his surviving spouse knew nothing about the coach.
I keep reading about the fire extinguisher (FE) circuit that can keep the hold from working, but I can't find a FE or any related wiring (I probably just don't know where to look).  On my generator monitor panel the FE charged light is lit and green.
I've owned several motor coaches but this is my first Newell and after my 400 mile trip home after the purchase I know know why I've always wanted a Newell, even though I previously owned a Prevost H3.  It did suck not having the genset running, but luckily the temp was perfect.....not too hot, not too cold so it was a great drive.
Any help appreciated.
Mike M.
near St. Louis

[Land Yacht]

What jumped out at me from your text is “the cooling fan does not kick on”. Could there be a shutdown circuit attached to the cooling fan? Most generators have over heat shutdown circuits.

[jorma]

I'm not sure, but I think the cooling fan is supposed to kick in as soon as the generator is running.  I only ran the unit for a few seconds at a time.  Do you know if it doesn't kick in until a certain coolant temp is reached?
Mike M.

[Land Yacht]

Mine starts as soon as I start the gen

[HoosierDaddy]

Jorma,
My Martin has a control box that manages the generator start up etc. Gordon rebuilt mine for me. Not expensive. The folks at Martin Diesel are very helpful as well.
http://martindiesel.com/

Maybe Gordon will chime in. He is our resident Generator Guru.

[rheavn]

Jorma,
My generator did exactly the same thing a few years ago. On mine, Kohler, there are four fuses on the control box mounted on the left side of generator as you face it. One of the bottom two fuses was blown. You have to replace with a slo-blo fuse. I got mine here:

https://www.amazon.com/gp/product/B007ZT...UTF8&psc=1

[Richard]

@"bestgenman" is on his way to the rally, he will pickup this thread soon, and you will have the most excellent help you can imagine.

[bestgenman]

Mike, I concur with Steve,  the cooling fan is 240V and wired directly to the output of the generator (ahead of any overcurrent protection such as a breaker).  The Martin control box looks for 240V in order to hold the solenoid in.  My bet is a broken wire on the AC output of the generator since you have voltage on one leg.  It's highly unlikely you have voltage regulator failure.  you'll need to look in the generator termination box rather than the junction box on the wall of the generator set's / Newell box.  

Yanmar manufactured engines of your vintage using  a two wire solenoid with a third wire not used.  Shortly afterwards, they switched to the three wire "hold in / pull in" version.   Your solenoid is working fine since it pulls in and doesn't have a seperate hold in circuit.

[jorma]

Thanks for the quick replies. Gordon, where would I look for the "generation termination box" and what does it look like?  I'm pretty good with mechanicals since we build and race cars, but we don't have generators (except in the trailer.....12KW Onan QD) and they are pretty foreign to me.  We did have a generator starting problem with my trailer when we got it.  After quite a bit of head scratching and even buying a new ECU ($$) we finally figured out the trailer had a poor ground from the factory.
Mike M

[HoosierDaddy]

Jorma, I believe the generator termination box is mounted right on the generator.