Need help with diagnosting my generator not starting

[tomevansfl]

A few days ago I went to my coach at the storage facility to "exercise" the engine and generator.  I had just got it back from Cummins Coach Care a few weeks ago for replacing the chassis batteries, changing the oil and fuel filters. The coach had been stored unused for about a month without use and I wanted to run the engine and generator for about an hour each to circulate all the fluids, etc.

The engine cranked just fine but the generator wouldn't even try to turn over.  I couldn't even hear a click when I priimed and tried to start it.  The light on the on/off switch lit up so I know power is getting to the switch on the dash.  I also tried the switch on the generator with no luck. 

I always turn the house and chassis battery cut-off to the off position to prevent vampire battery drainage while in storage. I cheched the breaker on the generator, but it hadn't tripped. I admit I didn't check the fuses in the front-driver's side panel under the driver's window to see if any fuses in there had blown.  Not sure if it may have been disconnected from the chassis batteries or what. 

Could Cummins Coach Care have forgotten to reconnect the generator to the chassis batteries? If they did, is reconnecting something I can do or should I take it back to Cummins Coach Care?

What is the next logical thing to check?

Thanks in advance.

 

[jacwjames]

There was a recent post on IRV2 with the same problem, I told them to check the 3 fuses under the small cover above the start button on the generator.  Can't remember what the 3 fuses protected but one had to do with starting. 

[Tom Cherry]

Sometimes Cummins will disconnect the wiring harness to prevent an AGS or an accidental starting.  I,m like Jim, if you had a light, I don’t know if that (disconnected cable) would allow you to prime.

if you find the 3 fuses and they are good, my next step would be jumper cables on the rear of the Genny.  Assuming you are comfortable shinning under there.  Then hook up to a car or truck.

now try to start.  If it doesn’t click or turn over, then something inside the Genny is the issue.  To beat a dead horse, I had the same issue…nada on a Onan 8Kw.  I put on booster. Bingo.  I eventually found that the ground stud was corroded.  Now…I spent a lot of time with a VOM.  I FINALLY figured out that if I slammed the battery tray in place, it would start…or maybe if I closed it gently. What was happening was the house ground cable was flexing when the tray was pulled out.  I had resistance from the Chassis Ground cable to the House ground cable.  NO resistance from ground to chassis, but some to house.  Bingo….a high resistance connection.  It was either a defective cable end….and we have seen those with absolutely no external corrosion but internal corrosion.  Drove a very astute member batty.

so…give it voltage from an external source.  If it cranks, then go to ground first.  Loosen the two nuts….one for chassis and the other for house.  Remove or clean or just rotate the cables side to side, with some tension still on the nuts. Bingo….that will burnish and clean.  No joy.  Check each end on the batteries.  Finally, chase the house (if that cranks the Genny) positive to the battery buss.  There is probably an 80 A ANL fuse there. Make sure it is good and also connections tight.

BTW, IF it is the cranking fuse, which is a ANL type, get a Bussmann IGNITION Protected fuse….exactly like what Monaco put in.  The cheaper ones fail.  Don’t ask HOW I know these things…

[tomevansfl]

Thanks guys.

I’ll be going by the storage facility tomorrow and I’ll check the fuses in the generator.

We’re going to a local county park campground this weekend andIf it isn’t the fuse I’ll consider crawling under the front end while it’s jacked up high enough on the levelers for me crawl under. 

[jacwjames]

The three fuses are

F1  Control Circuit 10 amp

F2   Starter Solenoid Circuit 10 amp

F3  Glow Plugs  25 amp

 

[tomevansfl]

Thanks Jim. I didn’t make it to the Rv today but will be camping this weekend and I will check them then. 

[VinceB]

On 11/30/2022 at 5:22 PM, jacwjames said:

The three fuses are

F1  Control Circuit 10 amp

F2   Starter Solenoid Circuit 10 amp

F3  Glow Plugs  25 amp

 

Just had a similar problem. jacwjames got me going again.

I had trouble finding the fuses, though. It is not intuitive.

Remove the access panel on your genset that is by the start switch. 10mm IIRC. You have to jiggle the panle around just right to get it off. 

The underside of the panel has provision to hold the radiator cap along with 2 fuses. The hose that the radiator cap is on is folded down into the cavity. Yeah, I know, odd.

You will pull that radiator cap up through the hole - that will unfold the radiator hose and allow you to access the 2 fuses that are mounted by the cap - follow the wires. The 25 amp fuse was "floating" by itself underneath the access panel. 

[tomevansfl]

Thank you for all of your help but I am a nube and feel completely stupid. 

I started poking around and tried the start button on the generator and found out just how inept I am with diesel enginees.  When I tried the start button I could hear the fuel pump.  When it delivered fuel to the generator the sound of the pump changed so I tried the start button and it started.  Apparently when Cummins Coach Care replaced the fuel filter (they said it only had one) they neglected to prime the generator.

Now I understand the generator more and have some trouble shooting ideas to start with if I have future issues.

Thanks again for all of your help.

[Tom Cherry]

1 hour ago, tomevansfl said:

Thank you for all of your help but I am a nube and feel completely stupid. 

I started poking around and tried the start button on the generator and found out just how inept I am with diesel enginees.  When I tried the start button I could hear the fuel pump.  When it delivered fuel to the generator the sound of the pump changed so I tried the start button and it started.  Apparently when Cummins Coach Care replaced the fuel filter (they said it only had one) they neglected to prime the generator.

Now I understand the generator more and have some trouble shooting ideas to start with if I have future issues.

Thanks again for all of your help.

All I can say is ETU, Bruti?  I think, and logically so, as the Genny ages, it is a bit more cantankerous.  I THOUGHT I had an issue.  But the two GENNY experts started it FINE.  BUT, they did a long or thorough PRIMING.  So, now, I prime when I start.  If I am going to need the AGS, I run the Genny as I drive so it is “feeling froggy” when we get to the CG or wherever I might need it…

[jacwjames]

I ran my generator out of fuel right after I got the rig in early 2009. Learned 2 valuable lessons.

1. I have a 128 gallon fuel tank and it runs out of fuel at ~30 gallons left in the tank, so a 75% usable capacity for generator.  Never ran out of fuel with engine so that is still a mystery I don't want to solve.
2. I had to prime my generator a looooooooooooooong time to get it to start. 

Glad you got it running with no $$$ involved.

[cbr046]

54 minutes ago, jacwjames said:

Never ran out of fuel with engine so that is still a mystery I don't want to solve.

With the FASS pump (which you have) you might have to loosen the XWS filter so the the FASS pump will prime.  After that it's sending and pumping through the CAPS / HPCR pump.  Starting shouldn't be a problem.

When I ran out of fuel in AL (pre-FASS) I had to cycle the lift pump probably 10x to get the ISC engine to fire.  Primary fuel filter, which I had just replaced literally in the middle of the road, was empty when I started.

So there *IS* life after running out!

- bob