2002 Diplomat Dies While Driving

[dickandlois]

19 minutes ago, fountaincharles2 said:

Rich, I have a copy of the Coach Manual that came with the Coach. Sorry I didn't mention it earlier, but I initially thought the Manual you were talking about was a Service Manual.  I don't have Word, but can get it.

With respect to the earlier question I had with respect to the Starter Solenoid, as I recall from a previous starting problem, when the starter solenoid wouldn't engage due to a loose wire, the dash panel did show lights as well as the tranny panel. That was several years ago. So, I may have answered my own question relative to the actual starter solenoid. My particular Coach may not be wired so as to kill all of the power if that solenoid were to cause a problem. Just trying to eliminate the Solenoid as a culprit.

Dave, There is a Switch mixed together with the Entry step that controls power the the Solenoid in question near the entrance . 3 position switch that has a center off  position . On / off/ on.

Where is that one set. one position should feed 12 volts to energize the solenoid in question.

Just make sure it is not touching a ground. with that you should be able to read 12 volts on what they mention as being purple in color that completes / energizes the circuit to ground.

Some info on page 307 covers the item in question. Not much technical info though!

Rich. 

[fountaindavid.jean]

That is a good point. There could possibly be a situation at that point. That panel has to get a ground from some place. Glad you thought of that little noticed switch. Thanks.

[dickandlois]

3 hours ago, fountaincharles2 said:

That is a good point. There could possibly be a situation at that point. That panel has to get a ground from some place. Glad you thought of that little noticed switch. Thanks.

Dave,

The switch ground is at the Board picture you attached .  You need to see if you read resistance from the point the purple would normally attach. Measure the resistance of the red wire to ground on the other terminal.  Then read the resistance between the 2 coil terminals. 

Second . the power is supplied through the purple from the switch you located. Should read around 12 volts DC at the switch and the wire located in the fuse box. When the sw is toggled, you will need a helping hand unless you have very long and flexible arms. LOL

Let me know what the reading are!

You are holding up very well at getting through the task.

Rich.

[dickandlois]

Dave,

Sent you a PM this AM with a PDF file I created that might help trace the circuit. Still not sure where the real issue is. Heat, component, loose connection or a fuse issue. 

Rich.

[manholt]

Just trowing something out...you mentioned Lift Pump.  Could it be a bad controller? Or lose wire at that junction?

[dickandlois]

9 minutes ago, manholt said:

Just trowing something out...you mentioned Lift Pump.  Could it be a bad controller? Or lose wire at that junction?

Good Morning Carl! Could be, bur with out power to a number of circuits on the Front fuse panel, that is an item to check after the fuse box has 12 volts to all the fused circuits. His fuse box has around 33 fuses.

Dave did mention that all the Spade style fuses checked good.

With heat damage too 3 relays and the sockets like 3 years ago, something caused it and they where replace. Everything work fine until now. When the coach set over night everything worked fine in the AM and he was able to drive on home.  Just hate intermittent issues. When things work the only thing you have working for you is, just bumping the right spot or wiggling the right wire.

Rich.

[manholt]

Dirty. lose or bad ground/wire connection!  You/I have been there before...Remember Adam's Prevost, 24V system?:

[fountaindavid.jean]

Rich, can't get to your PM. The email that you used wont' come in on the desktop that I am using. Use "fountaincharles2@gmail.com" and re-transmit the PM please. I tried to delete the other fountaindavid...email from FMCA forum, but can't find it in my Profile. Meanwhile, I'm will get DW to go out to the garage and assist me in talking the measurements that you asked about. Thanks.

[dickandlois]

1 hour ago, fountaincharles2 said:

Rich, can't get to your PM. The email that you used wont' come in on the desktop that I am using. Use "fountaincharles2@gmail.com" and re-transmit the PM please. I tried to delete the other fountaindavid...email from FMCA forum, but can't find it in my Profile. Meanwhile, I'm will get DW to go out to the garage and assist me in talking the measurements that you asked about. Thanks.

Information sent!  As requested.

Rich.

[fountaindavid.jean]

On 3/4/2020 at 5:57 PM, DickandLois said:

Dave,

The switch ground is at the Board picture you attached .  You need to see if you read resistance from the point the purple would normally attach. Measure the resistance of the red wire to ground on the other terminal.  Then read the resistance between the 2 coil terminals. 

Second . the power is supplied through the purple from the switch you located. Should read around 12 volts DC at the switch and the wire located in the fuse box. When the sw is toggled, you will need a helping hand unless you have very long and flexible arms. LOL

Let me know what the reading are!

You are holding up very well at getting through the task.

Rich.

The resistance for the small red wire to ground is 2 ohms, and the resistance between the 2 coil terminals is 4 ohms. The voltage at the switch where the purple connects is 13.6. I noticed that on your PM explanation you made mention of the Peach colored wire(with inline fuse) sticking out of the ignition socket. Not sure if I pointed out that that wire was only left there since I used it to jump that socket when the Coach died two years ago and I needed to get the Coach back home to work on it. I had the Board out to install the new Sockets and Relays.

[rayin]

About 5  years ago I had a similar issue. The engine would start normally, when I put the tranny in gear the engine died and would not re-start(dead ignition switch) for about 20 minutes. I called Good Sam ERS who sent a mobile mechanic To I24 rest area near Ft. Campbell KY. We both looked for the cause for almost an hour. The mechanic finally found a loose connection on a terminal block on the firewall that supplied 12VDC to the driver controls. He showed me the retaining nut was almost off, yet the loose wires made enough contact when cold the engine would start. When I put the tranny in gear the current draw was enough to break the connection. He tightened that retaining nut and I've never had that issue again.

[dickandlois]

On 3/5/2020 at 6:41 PM, fountaincharles2 said:

The resistance for the small red wire to ground is 2 ohms, and the resistance between the 2 coil terminals is 4 ohms. The voltage at the switch where the purple connects is 13.6. I noticed that on your PM explanation you made mention of the Peach colored wire(with inline fuse) sticking out of the ignition socket. Not sure if I pointed out that that wire was only left there since I used it to jump that socket when the Coach died two years ago and I needed to get the Coach back home to work on it. I had the Board out to install the new Sockets and Relays.

Thanks for the numbers !  Wit that information. The current draw of the Solenoid is around 3.5 amps and the power / wattage is between 40 and 50 watts. That is well with in the size of a 7 amp fuse used on many solenoids used in on the board. That fuse is pictured on the drawing picturing the part in question.   The numbers indicate that the Solenoid in question is good, When it is Cold. The fact that everything works when cool or cold something is changing with temperature .

FYI, the 50 amp circuit auto rest circuit breaker. is powered from a 150 amp circuit located on the rear run box. The wire is red in color and 2  gauge,  that powers the front fuse box . It is looking like there is strong evidence of a loose connection in the ground connection for the fuse box and / or even in the red wire supplying power from the fuse in the rear run box  mentioned above , But you did measure  12 volts at one end of the fuse. There is a possibility that 50 amp auto reset circuit breaker has failed. Remove the end closest to the CB. see if you still have 12 volts at both ends of the unit.( Lower left corner. it looks like it is held in place by nuts and washers, between the supply and the  wire powering the Solenoid ).

Intermittent problems are so difficult to find !!!! 

There are 3 -150 amp fuses in the same area. The other 2 supply power to the preheat-er grids in the intake manifold. The engine intake manifold heater supply wires are Red - 6 gauge 

The ground connection for the  front fuse box ,  Could share a common ground point in the rear run box area, But I have to believe the front fuse box ground is closer - like a common ground point behind and under the dash. 

No luck yet finding information on the front fuse box circuit board.

Rich.

Yesterday I was able to contact the Technical section of the REV group and got a better PDF file. With that information I will try to contact them again and ask for some info on where the front fuse box ground might be located. There is a ground ring on all 4 of the circuits, but it does not indicate on the  drawing where the 4 grounds are really located.

That kind of leaves it open to the possibility that all the grounds are closer to the items powered by the  larger 12 volt cables.  There is allot of steel frame work to connect the grounds to.

Is it possible  to forward some pictures of the backside of the board you posted earlier? 

[fountaindavid.jean]

On 3/4/2020 at 5:57 PM, DickandLois said:

Dave,

The switch ground is at the Board picture you attached .  You need to see if you read resistance from the point the purple would normally attach. Measure the resistance of the red wire to ground on the other terminal.  Then read the resistance between the 2 coil terminals. 

Second . the power is supplied through the purple from the switch you located. Should read around 12 volts DC at the switch and the wire located in the fuse box. When the sw is toggled, you will need a helping hand unless you have very long and flexible arms. LOL

Let me know what the reading are!

You are holding up very well at getting through the task.

Rich.

Rich, The resistance for the red wire to ground showed about 2 ohms. Resistance between the two coil terminals is 4 ohms. The voltage on the purple wire at the switch showed 13.6 volts.

 By the way, in your email explanation you mentioned the ignition socket had what appeared to be a fused wire. Not sure if you saw my initial explanation about the Board pictured, but that peach colored wire was a jumper wire I used to get the MH back home the first time it died 2 years ago. Again, that Board photo shown above was taken two years ago when I removed if for repairing the burnt relays/sockets.  I am trying to attach another picture taken today of what the Boards looks like installed in the MH.Thanks for your help and suggestions.

[fountaindavid.jean]

With respect to your question about the back of the Board. Not sure any pictures were taken two years ago. Otherwise, all of the wiring would have to be removed to get the Board out again. Tried to post a picture of installed Board yesterday, but for some reason I am not the best in the world at attaching photo's. Let me see if I can find an old picture.

[dickandlois]

I did not see a picture yet?

    Did the information I sent regarding the condition of the Solenoid, is well  with in the operating  parameters using the resistance and voltage readings you sent.

The chassis wiring  shows the power for the front board you repaired,  is supplied by a 150 amp auto rest circuit breaker located in the rear of the coach on the Engine Control panel.

My last post listed the wire size and gauge  of the wire running between the engine control panel and the front fuse panel. 

Remember a drawing is a representation of a circuit, not how items are  or where they are attached.

Rich.

[fountaindavid.jean]

Rich, sorry I have not had a chance to digest the valuable info you have worked so hard to develop. But, due to the storms in South Georgia last 2 days(Vidalia, GA), our Family Farm is experiencing some flood prong problems with our farm ponds and I am preoccupied with that at the moment as well as this. If there is not a problem in one area it's another. 

In any event, while I was out trying to get the readings(voltage and resistance) you asked for yesterday, while looking at the ignition switch etc, I remembered a problem with the dash radio going out some time back. All of this may be related. I think I will need to remove a "Kick Panel" and see how the under dash wiring Looms get to the outside compartment where the control board(front fuse box) is located. Maybe I can try and find some of the grounding points you mentioned above. Unfortunately, I don't think I will be able to complete this today.

[dickandlois]

You have other priorities at the time. Be safe working on the task at hand. 

You have had more then your share of rain this year. 

Farmers are and have always been challenged by the weather ! 

Rich. 

[kaypsmith]

3 hours ago, fountaincharles2 said:

South Georgia last 2 days(Vidalia, GA),

By all means, don't let the onions wash away, couldn,t stand a year without Cidalia onions, LOL! Good luck finding the hot no start problem.

[fountaincharles2]

What type of relay would I replace my KIB LR9806 with. I am not sure it is bad, but can't blame anything else at the time. Thanks.

[wolfe10]

fountaindavid.jean,

I just did an internet search for that PN and came up with many sources-- all under $80.

Is there a reason you don't want to just replace it with a new one?

As it has been awhile since this thread was updated, please tell us what symptoms you are currently experiencing that lead you to suspect the Battery Disconnect Latching Relay.

[fountaincharles2]

Rich and I have been discussing several possibilities as to why the coach instrument panel goes dark and the engine dies while traveling down the Interstate. Then after things cool down it starts right up(after about an hour and a half) and I am on my way again. That is...no dash lights period. As We have looked over the wiring diagrams, it seems to lead back to the front panel below the drivers seat. Not sure that is the culprit, but haven't been able to find where the power interrupt is while it's dead. Before I start to replace another Part, I am open to suggestion if someone has had a similar problem. Thanks.

Bret, to finish answering your question as to why I haven't replaced this part.....I was wondering what Part/Brand other folks may have replaced this particular Latching Relay with.

Edited May 28, 2020 by fountaindavid.jean
Clarification

[fountaincharles2]

Rich, I did find a photo of the back of my Board. Hope it's clear enough.

[f442485]

I had one at the shop that was doing the same thing. It turned out to be a defective ignition switch. The switch connector became loose and melted the power wire. sometimes it would work after it sat for awhile, but as soon as the current flow heated the connector back up it would loose connection again. It's easy to see the back of the switch with a flashlight and mirror. Just a thought

[fountaincharles2]

Just after my Coach shut down, I immediately started checking for any heat build-up under the Dash. The Ignition switch wires were cool to the touch. I have replaced parts over the past 2 years, but apparently have not been able to identify the "main" culprit(problem area/part). Each time this has occurred(loss of all power to the dash which kills the engine), it's the same sequence....your driving along and feel no power...you look at dash.....no lights in the dash and your coasting as you move over to the emergency lane and roll to a stop. This has happened at least 5 times over the past 2 years. Is this the sequence that the Coach you were working on experienced? Thanks.

[rossboyer]

You symptoms are similar to what I had on a previous motor home. The difference is that I would blow a small fuse that powered the computer. The problem was a bad solenoid in the transmission. We found that the same fuse while powered the computer also powered the transmission. Possibly, your wiring uses a self resetting circuit breaker.