2008 Navigator; Intellitec 73-00825 rear run box board bad. Workaround?

[Makalu]

I believe I've got a bad PCB board in my rear run box that is going bad. It is the 73-00825 board that has the 3 position rocker switch that allows someone to start the coach from the rear or select "front" to continue to use the key ignition. Then a momentary on/off switch to actually start the motor. I had my motor die on me 3 different times and got an "Eng Comm Failure" dash warning as a result. I replaced the switches on the board as I read a bad one can cause issue. The new switch came and I ruled it out as the problem.

 

But upon pressing slightly on the board, or moving the switch at all, I get intermittent power loss throughout the rest of the pcb boards in my rear run box and all the fuse lights flicker on and off. Then the motor recycles it's start procedure/lifter pump etc. 

So after talking with M&M RV Electronics, I send out the board for testing/repair. They should receive it Tuesday, though likely can't get to working on it for maybe 10 business days (bummer). Is there anyway I can bypass this board to start or move the coach while the board is being repaired?

[Frank McElroy]

Add a 15 amp fuse on connector J2 between pins 2 and 4.  This will in effect bypass this board.

38031552 (Schematic, Keyswitch Ignition).pdf 38040024 (Schematic, RRB Board 1).pdf

[Tom Cherry]

You might want to contact two of our electronic experts….who fix these boards….many SATISFIED members can attest….and way cheaper than the Candy Factory…

Paul Whittle @pwhittle    OR Frank McElroy @Frank McElroy

Frank is the FIRST PERSON….in the COUNTRY to figure out HOW to fix the Kongsberg CCM boards….a feat that has blown away many.

He has repaired way more Intellitec Monaco Proprietary boards used on the Dynasty and up…..than one can imagine….he just posted as i was typing….

Good Luck….  If you get “sticker shock” on the Candy Man quote…you MIGHT want to reconsider and use one of our guys….

[Makalu]

Thanks a bunch. If I'm understanding correctly I need to still have the board to bypass it? Unfortunately I already shipped the board off to get diagnosed/repaired.

Edited March 17 by Makalu

[Frank McElroy]

21 minutes ago, Makalu said:

Thanks a bunch. If I'm understanding correctly I need to still have the board to bypass it? Unfortunately I already shipped the board off to get diagnosed/repaired.

No, you don't  need the board.  You just add a fuse between pins 2 and 4 on connector J2 that would plug into the board.  

[Ivan K]

Besides the point but I often find it amazing how many simple switched circuits are made complicated and expensive, being custom and in no time obsolete, just to get few fancy looking diodes and on/off mosfets in place of easily replaceable relays,  integrated into a so called "controller". Makes sense using datalinks instead of huge wire bundles and some cool looking indicators can be helpful but often at a major cost to repair for a regular person. Certainly cheaper and easier to assemble new and profitable to service as they WILL fail, which I believe was and is the point these days everywhere. All these new coaches with touchscreen integrated systems will eventually make the few who will still know how to fix or work around busy, or the owners stranded.

[Makalu]

3 minutes ago, Frank McElroy said:

No, you don't  need the board.  You just add a fuse between pins 2 and 4 on connector J2 that would plug into the board.  

Great, I will try this tomorrow. Thanks Frank. You are a wealth of information! Curious where you came across the schematics for a 2008 Navigator? I'd love to have them.

[Frank McElroy]

41 minutes ago, Makalu said:

Great, I will try this tomorrow. Thanks Frank. You are a wealth of information! Curious where you came across the schematics for a 2008 Navigator? I'd love to have them.

They are the same as the dynasty/signature.  They are in our Downloads, under Electrical, Wiring diagrams.

41 minutes ago, Makalu said:

Great, I will try this tomorrow. Thanks Frank. You are a wealth of information! Curious where you came across the schematics for a 2008 Navigator? I'd love to have them.

Your other option is to turn on the ignition and use a wire to touch the starter relay lug circled in red to a 12 volt source.  This will crank the starter and start the engine.  If you want, just use the 12 volt wire that was on R1 that you removed.  Just touch it to the starter relay terminal circled in red.

[Tom Cherry]

57 minutes ago, Makalu said:

Thanks a bunch. If I'm understanding correctly I need to still have the board to bypass it? Unfortunately I already shipped the board off to get diagnosed/repaired.

Frank is our expert.  There is a 2008 Dynasty in the files.  Put WIRING in the search box.  Click on Everywhere….select FILES.

YOU MIGHT????  have the CCM Kongsberg system….doubtful….but you never know.  If so, there is a 2008-9 set.

[Makalu]

36 minutes ago, Frank McElroy said:

They are the same as the dynasty/signature.  They are in our Downloads, under Electrical, Wiring diagrams.

Your other option is to turn on the ignition and use a wire to touch the starter relay lug circled in red to a 12 volt source.  This will crank the starter and start the engine.  If you want, just use the 12 volt wire that was on R1 that you removed.  Just touch it the the starter relay terminal circled in red.

Would it make sense to you that I have this issue with the motor just shutting off on me if that intellitec board is going bad? Then displaying an "Eng Comm Failure" on my dash when it does? Even had a friend come out and plug in his Cummins Insite to the coach and he saw a code for an "Intermittent Ignition Power Loss" or something worded similar.

It has made the coach undriveable as you can imagine.

[Frank McElroy]

7 minutes ago, Makalu said:

Would it make sense to you that I have this issue with the motor just shutting off on me if that intellitec board is going bad? Then displaying an "Eng Comm Failure" on my dash when it does? Even had a friend come out and plug in his Cummins Insite to the coach and he saw a code for an "Intermittent Ignition Power Loss" or something worded similar.

It has made the coach undriveable as you can imagine.

I'm a bit surprised that this board would in effect cause the equivalent of cycling the ignition switch when you pressed on it.  I don't see on the ignition switch schematic where the ignition feeds through this board to the engine ECM.  If it does, then my trick to turn on the ignition and jumper that 12 VDC wire to the relay terminal won't work to start the engine.  If it doesn't work, I'll investigate more.

Most times an intermittent ignition loss signal is an ignition switch going bad. 

Com failure means that the dash cluster computer lost communication with the engine ECM because of a databus issue or an ignition lost signal to the engine ECM.

[Makalu]

1 minute ago, Frank McElroy said:

I'm a bit surprised that this board would in effect cause the equivalent of cycling the ignition switch when you pressed on it.  I don't see on the ignition switch schematic where the ignition feeds through this board to the engine ECM.  If it does, then my trick to turn on the ignition and jumper that 12 VDC wire to the relay terminal won't work to start the engine.  If it doesn't work, I'll investigate more.

Most times an intermittent ignition loss signal is an ignition switch going bad. 

Com failure means that the dash cluster computer lost communication with the engine ECM because of a databus issue or an ignition lost signal to the engine ECM.

This is what I was wondering about. But upon investigating the 3 position rocker switch that you can select "Front, off, Rear" with, I noticed it killing power to every board in the back run box and initiating a "Eng Comm Failure" dash warning. Even the guages up front were cycling from zero to full and back repeatedly until I turned the ignition off again. All I was doing with the switch was making sure it was set right on the PCB board. Then after replacing it I still had the issue. Then pressing slightly upon the board itself would sporadically kill power to the whole rear run box, literally every fuse light flickering off and on.  Needless to say, it has me puzzled.

[Frank McElroy]

2 minutes ago, Makalu said:

This is what I was wondering about. But upon investigating the 3 position rocker switch that you can select "Front, off, Rear" with, I noticed it killing power to every board in the back run box and initiating a "Eng Comm Failure" dash warning. Even the guages up front were cycling from zero to full and back repeatedly until I turned the ignition off again. All I was doing with the switch was making sure it was set right on the PCB board. Then after replacing it I still had the issue. Then pressing slightly upon the board itself would sporadically kill power to the whole rear run box, literally every fuse light flickering off and on.  Needless to say, it has me puzzled.

It could be that something was pulling down the ignition signal when you pressed on it.  You'll know tomorrow when you try the test start.

[Makalu]

1 minute ago, Frank McElroy said:

It could be that something was pulling down the ignition signal when you pressed on it.  You'll know tomorrow when you try the test start.

I will report back tomorrow, but I suppose it's possible the ignition signal is somehow at fault. And thanks so much for the insight. I hope I can get this sorted.

[Tom Cherry]

ERRRR?

What if the ignition switch is failing?  I know of several 07 & 08 Dynasties that had a switch issue.  BUT they had other symptoms like the Aladdin screen blanking out….but a failing switch could flaky?  Frank is the expert.  If you jumper and the issue goes away, then maybe the board??  But, if you bypass the board as Frank says and the issue persists….maybe the switch.

I’d troubleshoot and maybe put M&M on hold until the intermittent is resolved…

I’ll defer, of course to Frank…but if this is NOT a common problem and the board if usually robust….I’d eliminate the switch or a loose connection…

[Frank McElroy]

Ok, I think I figured it out.  Look at the circuit board schematic.  On that board the wire on J4 sends 12 vdc power to the engine ECM when the ignition has been turned on.  So, if relay K1 is starting to go bad, the ECM will lose the ignition signal - that's likely your problem.

That means you also need to connect a wire through a 20 amp fuse from 12VDC to the wire that was on terminal J4.  This will tell the ECM that that ignition is turned on.  That wire would need to either be switched or disconnected when the engine is off.

Now it makes sense as to why this board is causing your problem.  Should be an easy fix for the candy shop.

[MyronTruex]

Frank, you are too funny. Never heard them called the "candy shop".

Great advice Frank. 

[Makalu]

14 hours ago, Frank McElroy said:

Ok, I think I figured it out.  Look at the circuit board schematic.  On that board the wire on J4 sends 12 vdc power to the engine ECM when the ignition has been turned on.  So, if relay K1 is starting to go bad, the ECM will lose the ignition signal - that's likely your problem.

That means you also need to connect a wire through a 20 amp fuse from 12VDC to the wire that was on terminal J4.  This will tell the ECM that that ignition is turned on.  That wire would need to either be switched or disconnected when the engine is off.

Now it makes sense as to why this board is causing your problem.  Should be an easy fix for the candy shop.

So I just did as you recommended. I ran an inline 20amp fuse and connected 12vdc to the ECM wire. I just used the fuse as my "switch" if you will. 

Then I just touched a wire from a 12vdc power source to the starter solenoid you circled in red and it fired right up. NO "Eng Comm Failure" on the dash and it didn't die at all in the 15min or so I idled it and revved it up slightly. So this clearly seems to indicate some type of issue with the board, specifically that K1 relay.

One question I have is; I have no other fuse lights lit up in the rear run box when it's running now (I honestly don't recall if they are when the motor was running when the PCB board WAS working). Is that indicative of anything? Would I be able to drive the coach like this, temporarily of course?

I greatly appreciate your insight, Frank. You are a legend. 

 

[Frank McElroy]

20 hours ago, Makalu said:

So I just did as you recommended. I ran an inline 20amp fuse and connected 12vdc to the ECM wire. I just used the fuse as my "switch" if you will. 

Then I just touched a wire from a 12vdc power source to the starter solenoid you circled in red and it fired right up. NO "Eng Comm Failure" on the dash and it didn't die at all in the 15min or so I idled it and revved it up slightly. So this clearly seems to indicate some type of issue with the board, specifically that K1 relay.

One question I have is; I have no other fuse lights lit up in the rear run box when it's running now (I honestly don't recall if they are when the motor was running when the PCB board WAS working). Is that indicative of anything? Would I be able to drive the coach like this, temporarily of course?

I greatly appreciate your insight, Frank. You are a legend. 

 

Thank you for the kind words and I'm glad you were able to start the coach engine.

Yes, your coach is driveable.

As for all the other LED lights being out in the RRB, the left side of the circuit on the board you removed has a MOSFET that's used to power all the LEDs on all the boards in the RRB. 

So, without this power supply, none of the other LEDs on those boards will light but all the boards should function just fine.  If you look closely at the wiring diagram of the board you removed, there is a label called TEST.  You will see this label on all the other boards in the RRB wiring diagrams. All locations labelled "TEST" are connected together.  Basically the purpose of all those LEDs lighting up is to test to visually show that those individual circuits have power without the need of a voltmeter.

I thought why add more complexity to the procedure to start and run the engine with yet another set of procedures to build a circuit to operate those fancy wow indicator lights that you really don't need unless you are trying to troubleshoot problems in the RRB.

Glad you're getting to the bottom of the comm error problem.  I think your likely issue is the K1 relay or associated pcb connections.