Magnum Intellidrive. Engine Shutdown: On

[Joel Ashley]

Your photo seems clear enough. Either the wire to the solenoid is too short and stressed or the last guy that worked on it sloppily overtightened the mounting nut or misapplied the wire in the ring connector.  Replacing the connector, with the correct wire size ring, should be all that’s necessary, aside from double checking the other connections.  Make sure as you tighten down on the ring that you keep the wire lined up so it’s not turned to stress the wire again.

Be super slow and careful with wrenches in a tight area, though;  it’s easy to accidentally short across to a ground, sparking in your face and burning up a component.  Consider disconnecting the chassis battery bank temporarily.

Joel

[Mark Anderson]

Ok...so I got a new connector on and it seems like it wants to crank but it's like the batteries are low or it's not getting enough power or there's a ground problem.  I attached a video link so you guys can hear what it sounds like.  Batteries are fully charged.

https://drive.google.com/file/d/1WkDPEF_u6x1iTy0ts6ATsT0NvyMBqv-i/view?usp=drivesdk

[Eric Maclean]

Mark
If those batteries are fully charged I'd be checking  cables and connections for resistance problems too much volt drop or too much starter current draw (bad starter )
First try the boost button and see if the coach batteries helping out make a difference.
Remember on that vintage coach the chassis batteries aren't charged by the inverter charger unless there has been an echo charger or some other battery combiner installed.
Next read the chassis battery voltage while cranking this will give you an idea wheather or not the starter has too much draw or if there is a connection/ resistance problem.
While cranking the battery voltage shouldn't drop much below 9.6 volts

Hope this helps
Eric

[Dave Atherton]

Ok Mark, now we got engine to turn over but the batteries have to be charged to spin the engine.
My suggestion with all the attempted starts and engine does not start, the next place you will
need to check for air/fuel lock from cranking would be the return fuel pressure regulator. Location
on rear of head ( facing to front of motorhome) remove the return fuel hose facing on down side
of return fuel pressure regulator and attach a 1/2 clear plastic hose about 2 feet long and put open
end into a plastic container. Then turn engine over to see how much air is coming out of plastic hose.
Note: when fuel rail is charged with diesel there will be no air bubbles.

Last ECM just put on, the engine should start and run and idle. About the only functions that do not
operate will be minor that can be addressed. Again now that engine spins over with strong batteries,
you need to address the diesel fuel problem that may be air locked on fuel rail as Dave explained
the next step before engine will run. Dave atherton Retired Cat Mechanic

[Mark Anderson]

Hi guys...Just to be sure about something...what are the correct batteries that should be in there?  I replaced them with what I thought were the same, but maybe not?  I don't know.  It just seems like these batteries are providing enough juice.  They have 950 cranking amps, but is there something else I should be looking at?

I"m in a small town in Texas so my choices were limited on batteries when I bought these.  What kind do you guys recommend?

Also what is the best method to charge them?  Should I take them off or can I leave them connected?  I have always wondered the best way to charge these big batteries that are wired in parallel.

[Fred Brooks]

   Mark,
The Chassis batteries are considered "cranking batteries". They are designed to give short bursts of high energy (amperes). 950 cold cranking amperes would be the minimum for each of the 2 chassis batteries. The house batteries are "deep cycle" batteries and are designed to give you a long amount of "useable" 12 volts to run your interior support systems.
   Your coach has no means to charge the chassis batteries other than driving the coach. The Marquis came with a device called an Echo charger, Once the echo charger saw 13.2 volts for more than a minute, it latched unto the chassis batteries and sent a trickle charge to maintain them. There are similar after-market devises out there that do the same thing. A solar panel of 160 watts would keep everything maintained in storage if you had an Echo charger.
  Not sure if you got your engine started, if not, how did you charge the new chassis batteries? Fred

[Eric Maclean]

Mark
The batteries for the. Chassis are 31S series batteries the "S" stands for stud referring to the cable mounting configuration
There are several CCA ratings in that same size battery the highest being an 1100 CCA rating although when buying batteries you should always pick the highest CCA you can the 950s should do the job at hand .
In jour video of the engine cranking it sure sounds as though the batteries are dead.
The easiest way to charge those chassis batteries with out using an external battery charger is to simply connect a set of booster cables from the coach batteries to the chassis batteries and with the coach plugged in the inverter charger should charge them up for you .
I did that for a year or more before I finely broke down and installed a battery combiner.

FYI  the engines ECM has a small perasitic draw which over an extended period of time will discharge the batteries to the point they can't crank the engine much like yours are.

Hope this answers your questions
Eric

[Mark Anderson]

Update:   She runs!   I had to run a jumper cable from positive to the starter and it started right up...oh was a beautiful sound after 17 days of this.  So there is something up with that cable from the battery to starter.  I guess I'll replace both cable lugs first. 

What do you guys think?  Does the positive from the battery run straight to the starter?

[Eric Maclean]

Yes

[Dave Atherton]

Gentlemen, helping Mark get up and running is another reason why this forum is so great for
all membership. Different views, different ideas among members working together as a team
with one goal To help fellow member get up and running. Thank you, Dave Atherton Retired Cat
Mechanic

[Mark Anderson]

I agree.  I want to thank everyone for the advice and support to get me on the road again.  It is so nice to know that I'm not alone when something happens.

I would also like to summarize the problem and ultimate fix.

Original problem: No Crank

I had several issues:
1.) 1 dead battery and one near end of life (replaced both)
2.)  Wire came loose from connector on starter solenoid causing an intermittent slow crank/no crank
3.) Positive cable from battery to starter is bad causing slow crank. Most likely either connector at battery or connector at starter is bad.  I will be replacing both.
4.) At some point during the early stages of troubleshooting the ECM died.  I believe this was self inflicted but do not know exactly the cause.  It may have been when I was changing batteries, hitting the battery boost, or battery charging.  Most likely it was the battery change.

[Fred Brooks]

   Mark,
Glad you made it to the finish line and you did not loose heart. These coaches are difficult at times and we all understand that. Risk and reward is the on going battle but hang in there because we love the reward and the freedom it affords us. This is one of the reasons why we try to help!
   When you replace the lugs on the 3.0 gauge battery cables, Use "closed end" lugs and heat shrink to keep future corrosion out. Strip back the insulation until copper is seen, then crimp or solder.
  Blessings & Joy, Fred

[Dave Atherton]

Mark , one last thing question, will you be in AZ. this winter or planing on attending the Beaver
rally in the desert this coming January. The reason for the question if yes I, can help complete
your ECM replacement. I have Caterpillar ET where I can readout and print out all information that
is now programmed into the new ECM for your records and check out engine parameters.
Dave Atherton Retired Cat Mechanic

[Mark Anderson]

Will do, Fred.  Thanks for the tip.

Dave, we were planning on going to Arizona in the winter.  I will have to see about making it to Quartzite.  I know it it would be well worth the trip to have you take a peek inside our computer.

We made it to our next destination today.  It ran great, just like it did before.so that makes me feel good.  We are just outside Kerrville, TX at the moment and will be here until November then we are heading West.  So it may work out.  I will look up the info on the rally in Quartzite.

[Fred Brooks]

  Mark,
Great to hear you are on the road and all is good. I will be at the Beaver Quartzite rally in early January so perhaps we will get to meet.
  Enclosed a pix of how far corrosion can migrate up under the insulation on a battery cable, especially if it is an "open-ended" lug. I pulled the insulation back to reveal the hidden resistance. Fred