[hypoxia]

I have had intermittent starter engagement for some time, it kept getting more frequent, 2020P Coach 1482.  It always started from the engine compartment switch.  I think (hope) I finally resolved it.  There is a Silverleaf Rear Load Panel in the engine compartment with relays and wiring that go to the starter relay (Solenoid) mounted on the starter.  There is a Black/Red Starter Solenoid wire that goes to the front Fuse Panel where the air compressors are.  I found a K31 Relay in it which was powered whenever the Key Switch was rotated to the Start position.  I changed the relay on principal.  The engine has started every time since then (knock on wood)

Starter Wiring 2.pdf Size: 326.56 KB  Downloads: 9

   

START CIRCUIT CUMMINS 2010-Model.pdf Size: 229.62 KB  Downloads: 7

FCLC SPYDER FRONT RELAY BD.pdf Size: 1.18 MB  Downloads: 4

[hypoxia]

I edited the title and added the engine start wiring diagram. I am still having intermittent starter when using the key switch, the schematic should make it easy to pinpoint the problem the next time it fails.

[[email protected]]

I edited the title and added the engine start wiring diagram.  I am still having intermittent starter when using the key switch, the schematic should make it easy to pinpoint the problem the next time it fails.

Jim, its great that you were able to get the wiring schematic. Those can be invaluable. So you are still having starter engagement issues? Looks like all you have left is the key switch. It looks like the K23 relay is only for the ECM, so that would only cause issues with the engine not starting, but it would still crank. The other reason I would say that is that both the front and rear start switch rely on the K31 relay so I do not think that would be the issue if it only is a problem with the front starting only. Just my 2 cents.

BTW how were you able to come by the schematics? Did Newell provide them to you? I have heard there is not much for our older coaches, seems weird to me that they did not keep the schematics for our older coaches, especially since they occasionally still work on them.

[hypoxia]

The next check is Junction 177A-B-C in the front panel. If power is there then next is the top terminal of the rear start switch. If no power is there then there is a wire problem between the front and rear, IMHO. I have replaced the start switch previously. It has been intermittent for a couple of years, sometimes months apart.

Newell supplied the diagram yesterday.

[[email protected]]

The next check is Junction 177A-B-C in the front panel.  If power is there then next is the top terminal of the rear start switch.  If no power is there then there is a wire problem between the front and rear, IMHO.  I have replaced the start switch previously.  It has been intermittent for a couple of years, sometimes months apart.

Newell supplied the diagram yesterday.

Solid plan, split half method, start in the middle and work towards the end that is showing the issue. Since your issue is intermittent, you may think about wiring in a temporary light to the 177A-B-C terminal so that you can spot it readily when it happens. Is there an easy way to run something up to the drivers area to keep an eye on it? 

I notice there is a 5 pin plug near the start switch, is that the plug for the start switch or a separate plug? That may be worth checking. I am not sure about what kind of plugs Newell is using but sometimes contacts in plugs can be an issue. 

FYI, I am an industrial electrician, I have always loved troubleshooting difficult problems and finding solutions. 

Glad that Newell provided you the diagrams!

[hypoxia]

I was a ship without a rudder until the diagram arrived, now the path is clear. I always welcome input, I did spend time as an Avionics Tech so I have chased a wire or two in the vacuum tube days.

[[email protected]]

I was a ship without a rudder until the diagram arrived, now the path is clear.  I always welcome input, I did spend time as an Avionics Tech so I have chased a wire or two in the vacuum tube days.

Yes, I have done a little bit of trouble shooting on mine and it has been: start at a device and trace method. Luckily I have a fox and hound (circuit tracer) that I can use to follow the wire without having to physically trace the wire out. I had to do that with my fridge lock, which reminds me I need to pull the fridge out to finally fix that issue.

[hbens]

I was a ship without a rudder until the diagram arrived, now the path is clear.  I always welcome input, I did spend time as an Avionics Tech so I have chased a wire or two in the vacuum tube days.

I was an AT when I was in the US Navy. They taught us to split the problem in half and keep doing that until you narrow down the problem.
I worked in a shop on a bench so we had simulated inputs. One of the first checks was "knob-ology" to see if a knob was in the wrong position.
I still use that now common sense approach to fixing things.