Author Topic: C9 will not turn off w/ignition key  (Read 4038 times)

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Offline bburgess6

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C9 will not turn off w/ignition key
« on: January 02, 2012, 12:52:07 PM »
Hello All

Picked up new to me 06 Beaver Monterey.  At least half of the time the engine will not turn off w/the key.  Turned off chassis battery switch (I know you're not supposed to but desperate) and it still ran - turned off house disconnect, chassis disconnect still off and it stopped after a couple of surges.  Where should I start my search?

Thanks for your help,

Brad Burgess
06 Monterey
Kindest Regards,
Brad Burgess
06 Monterey C9

Offline Brett Wolfe

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Re: C9 will not turn off w/ignition key
« Reply #1 on: January 02, 2012, 12:59:55 PM »
Brad.

Sounds like the key is not turning off power to the engine.  Is this a new problem, or has this always happened since you got the coach (i.e. wonder if someone may have mis-wired it)?

When you turn off the key, do other items that only work with the ignition on continue to work (when they should not)?

For example, on most, the dash HVAC fan will only work with the ignition on.  If it/other items that should cut off with key off continues to work with the ignition off, either the ignition switch or ignition solenoid (not start solenoid) is bad.

If this is what is happening, start by tapping on the ignition solenoid-- it may be hung up.  This would be a temporary fix, with solenoid replacement needed. 

Let us know specifically what else is not operating as it should and perhaps you or someone with the same coach can pull out a wiring schematic and see what those items have in common.

Brett

Offline bburgess6

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Re: C9 will not turn off w/ignition key
« Reply #2 on: January 03, 2012, 12:55:45 PM »
Hi Brett

Thanks for the input.  I was at the coach this morning and it worked ok - also seems to happen more when the engine has been running for a while and everything is hot.  When I can duplicate the problem I will use your trouble shooting advice and report back.

Thanks Again,

Brad Burgess
Kindest Regards,
Brad Burgess
06 Monterey C9

Offline Doug Mihoky

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Re: C9 will not turn off w/ignition key
« Reply #3 on: January 05, 2012, 09:36:57 PM »
Hi Brett,

Just curious, but just where is the ignition solenoid located?

Thanks,
Doug
C-7
« Last Edit: January 06, 2012, 05:43:14 AM by Brett Wolfe »
Doug Mihoky
C7, 2005 Tropi Cal LX

Offline Brett Wolfe

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Re: C9 will not turn off w/ignition key
« Reply #4 on: January 06, 2012, 05:48:56 AM »
Doug,

Your coach maker makes that decision, but it is generally in the dash area or in the left front most basement (front of driver's tire) close to all the fuses.

Its function is to take the "on/off" signal from the ignition switch and turn on/off power to all the things that are only supposed to be hot when the ignition is on.

Its reason for existence is that there are too many loads to have them all run through the ignition switch, so the ignition switch's only load is the <1 amp needed to close the solenoid.

They can fail open or closed. If failed in the closed position (power on all the time, even with key off) it is often due to a pit in the contact surface not allowing the contact to retract. So, sometimes, a light sharp wrap with a screwdriver handle, etc will temporarily free it up.

Brett

Offline Dale

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Re: C9 will not turn off w/ignition key
« Reply #5 on: January 06, 2012, 06:39:32 PM »
Doug, Brett is correct. CAT engines do not require a electric or tank pump. So most rigs do not come with one. Also their is no Fuel solenoid. What you have is an ignition switch, which turns on the ECU, which power the started solenoid to the starter. Once the engine turns over, the HEUI pump is turning over and pulling and supplying fuel. So if your rig is not going off, when  you turn off the key. Then start looking at the ignition switch assembly. Once power is cut to the ECU, it will turn off the actuator pressure valve in the HEUI pump I believe. Which by the way controls the injectors fuel flow. So look at the gauges, dash etc to see what is going on

dale03SeYa
CAT 3126E
DaGirls Rv
Alfa SeYa 2003, Cat 3126E 330Hp
08 Jeep Liberty - Roadmaster tow and Air Brake system
940Watts MPPT Magnum 2800W Inv/Chg, 660AmpHours

Offline bburgess6

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Re: C9 will not turn off w/ignition key
« Reply #6 on: March 25, 2012, 03:47:05 PM »
Mystery Solved!

Hello All

OK - not an engine or ignition switch or ignition solenoid problem.  I was at Chuck's Speed Shop in Phoenix having the coach portion of a US Gear tow brake installed.  When I pulled in to the lot, once again the engine would not shut down.  Chuck's has several very talented techs and so they came out to look at the situation while the engine was still running.  Couldn't immediately find the issue so they asked that I disconnect the toad and move the coach inside (ignition key in the coach was in off position at this point.)  Disconnected the tow bar and then pulled the electrical cable from the rear of the coach - instant silence!

Long story short - there is a wire in my trailer connector that is labeled "battery" and is a charge wire to keep the toad battery charged.  This wire was fed from the bus that is activated by the starter solenoid.  When the folks that wired the lights on my toad did their installation they did not put a diode in this line at the toad.  Consequently, the toad battery back fed the ignition bus so that even with the ignition solenoid off the bus was still hot and feeding the ECU.  If I had not unplugged the toad with the coach engine running and the coach ignition key off this would have been a very interesting problem to trace!

Kindest Regards,

Brad Burgess
06 Monterey C9 
Kindest Regards,
Brad Burgess
06 Monterey C9