Engine trying To start Without Key in

[wracinti]

Just drove my coach 3 hours no problem, had parked next to house jacks down slides open getting last of stuff out and i heard a noise from back of coach like the engine. Go outside and sure enough the engine is cranking over trying to start and it would not stop. NO KEY IN IGnITION. Only way could stop it was to put key in and turn like trying to start then engine would start and idle. When turned key to off position engine would stop for a second then start to crank over again trying to start. Putting slides in bringing it off jacks and unplugging from shore power did nothing to help, didn't think it would. Anyone heard of this? Its at Cummins now, they sounded like they never have come across this.

[hohenwald48]

Had a Chevy Vega (showing my age now) that did that. I found a wire that had melted thru and touched the engine block.

[Buly]

Stuck starter solenoid?

[twinboat]

The starter mounted, or more likely, the smaller slave solenoid is probably stuck.

Odd that the shop doesn't know this.

[willipaul]

throw the chassis disconnect battery switch...that should shut her down....

[wracinti]

After a week at Cummins can't reproduce the problem. Everything points to water getting into storage bay behind rear wheel where a lot of electricals are. We drove 3 hours in the rain just before it happened. Tips on sealing storage bays that leak water into them?

[V3600]

Stuck starter solenoid or not, the starter should not have any juice getting to it in the first place.

[Rotten-Red]

Originally Posted by wracinti

After a week at Cummins can't reproduce the problem. Everything points to water getting into storage bay behind rear wheel where a lot of electricals are. We drove 3 hours in the rain just before it happened. Tips on sealing storage bays that leak water into them?

Use lots of roofing cement, available in the one gallon cans at any home builders supply. Clean the area the best you can where you suspect it could be leaking. Then apply the roofing cement (tar) liberally to the area.

[Skiddy]

Originally Posted by Buly

Stuck starter solenoid?

that's what happened to my po. a couple times after it was stared the starter kept cranking and took out the teeth on the starter. only way he was able to stop it was unhook the batteries.

[Ljwt330]

Originally Posted by wracinti

After a week at Cummins can't reproduce the problem. Everything points to water getting into storage bay behind rear wheel where a lot of electricals are. We drove 3 hours in the rain just before it happened. Tips on sealing storage bays that leak water into them?

This makes perfect sense, IMO^^.


There is always power to the starter motor as it has a cable bolted to it that runs directly from the battery. The motor does not spin, however, because that power is wired to a switch inside the motor that is normally open. That switch is closed by the activation of the solenoid, causing the motor to spin.



Your problem cannot be caused by a "stuck" solenoid because the solenoid cannot get "stuck" unless it is first energized. Under normal circumstances, the solenoid cannot get energized unless the key is in the "start" position.


For your engine to try to start without the key in the ignition, there must be a contact somewhere along the wiring that is supplying 12v to the solenoid wire. The logical place would be somewhere along the wire harness from the solenoid to the ignition, if not at the solenoid terminals themselves. From your description, the compartment holding the wiring is certainly the main suspect. Without doing a detailed dissection of the the electrical components in the compartment, you may never be able to duplicate the problem. Best bet would be to do as you plan--waterproof the compartment/electrical area and hope it never happens again.

[twinboat]

Originally Posted by Ljwt330

This makes perfect sense, IMO^^.


There is always power to the starter motor as it has a cable bolted to it that runs directly from the battery. The motor does not spin, however, because that power is wired to a switch inside the motor that is normally open. That switch is closed by the activation of the solenoid, causing the motor to spin.



Your problem cannot be caused by a "stuck" solenoid because the solenoid cannot get "stuck" unless it is first energized. Under normal circumstances, the solenoid cannot get energized unless the key is in the "start" position.


For your engine to try to start without the key in the ignition, there must be a contact somewhere along the wiring that is supplying 12v to the solenoid wire. The logical place would be somewhere along the wire harness from the solenoid to the ignition, if not at the solenoid terminals themselves. From your description, the compartment holding the wiring is certainly the main suspect. Without doing a detailed dissection of the the electrical components in the compartment, you may never be able to duplicate the problem. Best bet would be to do as you plan--waterproof the compartment/electrical area and hope it never happens again.

The signal ( S ) wire on the starter motor solenoid is controlled by a remote mounted relay. That remote relay is what gets the start signal from the ignition switch, thru the neutral safety system.
This is done so you don't have 80 feet of wiring carrying the starter mounted solenoids higher current.

It looks like a regular old Ford type solenoid and that would be in the electric bay area, typically on the chassis rail, subject to all sorts of road grime and corrosion.

The remote relay sticking or activating thru corrosion will cause what happened.

Here is a typical set up.

[wracinti]

Thanks all. Cummins has been good, does not want to give it back without identifying problem for fear it would act up when i"m not around and overheat possible fire hazard. Talked to them Friday, they did mention i believe looking for a relay but Spartan told them battery bay which there are no electricals there. I pointed out the next bay up from the rear on passenger side has a bunch of electricals in so we'll see. I will definitely bring up the relay.