Main Engine Will Not Start

[jswigart]

I have a 2007 HR Navigator and cannot get the main diesel engine to start. Turning the ignition key will get the gauges to work but nothing else--no sputter, no clicking, nothing. The chassis batteries are OK and I can start the generator. I checked fuses et al in the rear running box in engine bay and they were OK. I did notice the Battery Isolator Relay was REAL HOT to the touch (the green LED was on). Is it possible that a defective BIR will keep you from starting the main diesel engine?

[trackman]

A relay is just that. It allows current to pass. With it being hot it is getting current. Passing that current to the next phase could be the problem. Check the wiring from the relay to the next circuit for touching wires or loose connections

[Mr_D]

Had that happen a few months ago with our DSDP. Turned out to be a bad starter. Wish it had been a solenoid, they're MUCH cheaper to fix! Cost us $1002 plus, had we not had Coach Net towing it would have been another $700 for the tow.

[Twomed]

Check relay box in the rear for circuit breakers marked IGN small silver look like fuses. They are prone to failure and will kill all start functions while letting guages etc. start up. Try switching one with another or a good 20amp fuse.

Hope it's this easy!

[Steve Ownby]

Could the switch in the rear run box that allows you to start the coach from the rear have gotten switched? If the answer is no, then Try switching that switch to the rear and see if it will start from back there. Remember you have to turn the switch on up front.

[YC1]

That bird relay runs uncomfortably hot to the touch. Since it was hot you must be plugged into shoreline or have solar panels ???

That aside the relay is a know failure item. I switched mine out for the third time this weekend on my 2008. Since I have known about this I keep an eye on the voltages on the large terminals when the soleniod is hot (engaged). The voltage on both the large terminals should be so close to identical you can barely detect a difference. If you see more than 1/5 volt difference the solenoid contacts are fouled and both banks are not getting full use from the solenoid. The solenoid provides a path for charging current from shoreline/charger, alternator, solar etc. It will not be the source of not turning over. If however your engine batteries are not really getting charged through the BIRD then your engine batteries could be to low to function anything with a high current demand. If you don't have a voltmeter handy you can unplug from shoreline, turn the battery switches off, and stack the two large cables attached to BIRD onto one post. Turn switches back on and plug into shoreline. Let it charge and check your EMS panel to see if your charger is supplying some hefty current. If so let it charge at least 30 minutes and it should start up then.

[YC1]

If the previous response does not help take a look in the front run panel under the driver outside cabinet where there are lots of fuses and relays. Be sure you are in neutral of course or no joy. I am going to attach a bunch of schematics and diagrams that might be useful.

[jim.smithjr]

Make sure your transmission is in neutral. Turn on the key and touch the N button.

[jswigart]

First thanks to everyone for advice; however, still no luck. Don't believe I have a transmission problem--lit in neutral and the NEU Safety LED is lit in rear running panel. Tried starting from rear panel, had loud humming noise on right side of engine near manifold which I believe would be the fuel pump?..Noise went out after about a minute or two. When I pressed the rocker start switch still no crank of starter, but I did get LED indication power was going to starter relay. Was able to get under RV to some degree and smack the starter with a hammer but no luck there either. One old time trick I didn't do was short out the starter to see if it would start--too scared to try this laying under the RV. Don't believe I have an electrical problem except for maybe a defective starter solenoid? I had the generator and my Jeep hooked up just to make sure there wasn't a battery problem. Guess I'm going to have to call Cummins. Anyone have a starter replaced before? If it comes to this I hope they can jack it in place instead of having to tow it.

[YC1]

If you can get a voltmeter on the starter solenoid check the voltage while someone is turning they key. Make sure you are clear of any moving parts of course. If you have to connect a long wire and run it to a safe place. Just because you have jumpers on the engine batteries does not mean you have a good path to the starter solenoid. Since you do not hear the starter solenoid clicking then following the voltage will tell you lots of great information and if the solenoid happens to be a seperate part you can change it easily. You may even be able to remove the solenoid and check it with a set of jumper cables while out.

The attached picture shows the starter on my 08 400 isl Cummins. The solenoid does two things. It connects heavy current to the motor and engages the starter gear with the flywheel gear.

I can't see in the picture but there should be a small terminal that controls the solenoid. You should see voltage on that when someone turns the key. If not a simple jumper from the large terminal that is fed by the battery to the small terminal will make your day exciting as that monster roars to life.

[boaterok]

Had a similar problem and the awning wasn't all the way in. Drove me a little more crazy than I already was

[lonestarace]

Originally Posted by YC1

The attached picture shows the starter on my 08 400 isl Cummins. .

picture wouldn't load for me?

[D Barber]

Have you tried using the boost button to start your engine?

[YC1]

Originally Posted by lonestarace

picture wouldn't load for me?

Do you see a pdf? If so does it ask if you want to download or save it? If so try saving to your desktop and then try to open it.,