Chassis Battery Disconnect - FRUSTRATED

[CorinthWest]

Well, this is my first post to my first RV website ever.  Greetings all.  I am obviously writing this out of desperation.  Background: I purchased a 2004 Vacationer 37PCT (gas, W24 Workhorse with an 8.1) and have been fixing the myriad of issues with it (and there are a LOT).  Aside from parts no longer being available since Monaco went out of business years ago, I am finding SOME technical information difficult to locate as well.  Case in point, and the reason I subscribed to this website, the previous owner must have had an issue with the chassis disconnect switch.  When I got the coach, the switch was completely missing, and was replaced by a bolt and nut (scavenged from the guts of the original disconnect switch internal parts).  My guess is that the switch let them down at some point and this was their "fix" that never got "fixed".  He didn't even bother to tape it up....geez.  ANYWAY, there are 4 cables to the switch, one is the battery (obviously).  I am assuming another large cable goes to the starter.  I have the OEM schematics for the coach, but they are wrong (shows dual batteries and no disconnect).  I know this is wrong because I can see the original switch in pictures of other Vacationers.  It is located in the RF basement, to the right of the forward power distribution panel.  Here is a picture I found of another coach with the identical switch setup. (https://dreamfindersrv.com/RV/7707705/BIG_PICS.htm - I think it is the 8th or 9th picture from the end, black box next to red disconnect knob) I've replaced the switch, and it appears the cables will only reach in a certain way.  But this ties the battery cable and the starter cable together on one side of the switch, and there is a slight parasitic drain on the connection (probably PCM/TCM). The remaining 2 cables (smaller) are tied together on the other side of the switch.  I've called Monaco - no help.  I've called 3 different ex-Monaco dealers, and they all act like I am from Mars.  I'm trying to put this back the way it belongs (factory OEM), and I am looking for information (schematic?) on this particular switch.  I have spent DAYS researching this, and I am REALLY frustrated.  I need to know if the starter and battery cables go to one side of the switch (with the resulting slight parasitic drain), and the "other" 2 cables go to the other side.  Is this how it is supposed to be?  IE.  the battery "disconnect" doesn't actually FULLY disconnect the chassis battery.  However, this configuration would also lessen the load through the switch when starting since the battery and starter cables are "permanently" bonded to the same terminal on the disconnect switch.  I can't believe I can't find anything on this, and no one seems to know the answer.

Any help would be VERY much appreciated.  I'll add you to my Christmas Card list!

Edited February 28, 2022 by CorinthWest

[DavidL]

Hi CorinthWest,

Some comments - meant to be constructive:

When you are posting thoughts, especially long ones, and especially technical ones, use paragraphs so the content is readable.

Post pictures of the "switch" you have.

The link you post of the other RV - that is a website that has many pictures - which one are you referencing?  (EDIT: I reread and within your text I see you tried to call out the pic)

You say you have a schematic - great!  post that so that will help someone help you.

 

Without the above, it's really hard to provide you the help you deserve.

 

 

Edited February 28, 2022 by DavidL

[SteveJ]

Welcome to another Vacationer Owner! Not many of us on this site . . mostly DP's - at least the active ones

Your switch probably 'broke apart' on a previous owner. Mine did shortly after I bought it in 2018. They were poorly built and storing anything in the FR basement put pressure on that switch. I lost the house one also, both of which I replaced with marine grade switches. The wiring is as you see it. I just 'transferred' to the new switch with only a little tugging since the switch was bigger/heavier. It looks as if they are split - 2 & 2.

I have the 2004 HR/LaPalma wiring diagrams - only partially helpful and not always accurate. And it doesn't cover the Engine side wiring at all. Monaco left it to Workhorse or Ford to provide something, which they don't.

I have 4 years of hunting down issues on a vacationer/workhorse so don't be afraid to email me anytime

 

IMG_0004.HEIC IMG_0007.HEIC

Sorry, I noticed the pictures didn't come through as jpegs. Sometimes the happens on my Mac when transferring by messages. If they don't open for you, let me know and I will try to post them another way.

 

[CorinthWest]

Constructive criticism is ALWAYS welcome, David.  I can use all the help I can get (just ask my wife).  Anyway, thank you for the reply.  Yes, my level of verbosity is directly proportional to my level of frustration - LOL.  Sorry for the lengthily post.  I said the pic is the 8th or 9th from the end.  But here is a pic of my installation (new switch).  I'm also attaching the OEM Monaco schematic per your request.  As you can see, it is definitely wrong (I only have 1 battery, and there is definitely supposed to be a disconnect switch here). 

Thank you for the reply, Steve.  Yes, I think you are right when you said "It looks as if they are split - 2 & 2".  I can't see any other way the cables can be routed, but I want to be sure, particularly because of the inherent parasitic drain.  But I didn't have anything to compare it to since it was a mess when I got it.  Yes, you make a good point.  I replaced it with a cheap OEM.  I probably should have gone to a better quality marine disco.  Hindsight, and all that.  If/when the house disco goes, or this one breaks again, I will replace them both with better quality.  Thank you for the advice (where were you LAST week - LOL - just kidding).

I really love this coach.  It's not my first, but it's the best in a long line.  But it was in really bad shape when I got it, although it LOOKS good (the IMPORTANT thing - LOL).  The best thing about this coach is the engine purrs like a kitten and the trans shifts beautifully.  Heater and A/C(s) work good and gen runs good - since I worked on it, that is).  Other than that, almost everything else was broken.  I have 3 pages of stuff I have fixed (single line spacing), and 2 more to go.  What can I say, I'm a glutton for punishment.  Replacing exhaust now.  Already did the tires and battery.  I keep telling myself that when I am done, there is nothing else that can go wrong - LOL!

Thank you again, Steve.  Really appreciate your input.

[CorinthWest]

Steve,

Those files did not translate to .JPG's.  What are they?  Also, I have a Workhorse chassis schematic if you ever need it, and I'm building a fairly good supply of spare parts because of all the work I am doing.  Not sure how to get you my personal email.  Can you PM me and I'll send it to you?

[SteveJ]

The wiring diagram you are referring to explains the aux start switch (on the dash), not the cutoff, as least that is what mine shows. The cutoff is not covered, either house or engine. And we certainly don't have an engine preheat so the diagram probably relates to DPs with something 'like' it on gas models. Again, nothing that Monaco published is always correct for a Vacationer.

Not sure if you have ever been to the REV factory and see them cutting/splicing the same wiring harness for 5/6 different models but I'm guessing Monaco did the same thing and them tried to document after the fact. My Vacationer seems to have another larger black wire along with the cable wrap at the cutoff switch - not sure if it might be inside the wire wrap? But mine looks like it is all original.

Those files were pictures but when I use air drop of messages to move from my iPhone to Mac Air, they use that format. Resend as jpegs. I'll PM you and I'm on workhorse also

[CorinthWest]

Agreed - I have found Monaco documentation to be less than adequate (understatement).  Some of it matches, and some of it doesn't.  It's a crap shoot.  Yes, as for the AUX START (Boost), THAT was broken too.  He had blown the F55 fuse and never replaced it - probably because he didn't know where it was.  Once I replaced it, Boost worked.  Just one of HUNDREDS of problems.  But I'm getting there.....lol.

Bought a lot of stuff from REV, but never been there.  Maybe when I get this thing rolling.  It's got some bady damage (not bad) and I heard they do pretty good body work.

As for your last 2 sentences, I'm curious.  The BIG black cable with the loom around it is the battery cable, and it goes into the bottom center of the switch.  Right next to it is a separate black cable (slightly smaller) that also enters the bottom center of the switch.  Then there are the 2 red cables, one on either side.  But inside the switch, the battery cable goes to the left lug, along with the left red cable, and the other black (smaller) cable goes to the other lug along with the other red cable.  Confused yet?  I am....LOL.

 

Ohhh, PM!

[Tom Wallis]

Here is the schematic I've been using for my Monarch which looks just like yours. As has been stated about all the schematics, sometimes it's helpful and sometimes not. The important thing for you is that it shows the disconnect switch is disconnecting the battery from the starter.Motorhome Wiring.pdf

[cbr046]

CorinthWest, although I'm not part of the official welcoming committee (LOL) I'll say welcome to Monacoers.  👍

When you get a chance you might create a signature or update your profile with more info.  Most people put the type of coach and resident city.  Not a big deal but it helps the rest of us with familiarity. 

One thing I didn't know I was missing is in the upper left side of the wet bay there's a switch to automatically turn on the light so you can see your poop exit the building in the dark.  If yours is missing or broken those switches are on Amazon https://www.amazon.com/gp/product/B093F89S9B/

Good luck with your project.

- bob

[CorinthWest]

Thank you, Tom.  My Christmas card list is getting longer!  LOL

I don't think the schematic you provided is the right one.  I'm fairly sure the starter is the one thing that DOESN'T get disconnected by the switch.  But I'm going to check it out.  Thank you.

[CorinthWest]

Thank you cbr046!  And another name goes on my Christmas card list.  LOL

Yeah, I already figured that out - and of course, mine was broken, like everything else.  LOL

Here are 3 dilemma's that baffled me that you might find interesting - the first is an extra connector up by the radiator over flow tank.  I found it in the Workhorse chassis schematic - it's for a low coolant sensor, that was not installed on this chassis.  The second dilemma that I haven't figured out yet is the "ACC" switch on the dash.  The owners manual states it is for auxiliary equipment, and the schematics show an empty connector in the dash.  But I don't see anything controlled by this switch, and I haven't found the connector.  The third dilemma is the TPMS low tire pressure warning light on the dash.  I called Workhorse and they said they didn't make a TPMS system for this chassis, but they did engineer the light into the dash in anticipation of delivering the system at some point in time - which they never did.  Not sure how accurate this info is, however.

Anyway, back to the disconnect switch.  Thank you for your input.

[Chuck B 2004 Windsor]

Under the main Monaco umbrella There are two main coach brands, Monaco, and Holiday Rambler. 

The HR brand is broken down to diesel and gas.  The gas models are broken down to 2 workhorse chassis, manufactured by Ford and Chevrolet.   Depending on year and model, the live in house box is the same.  

Around 1997, Monaco purchased the HR brand to get the rights to the HR Aluma Structure outside wall.  The 1998 Diplomat was built on the Aluma Structure outside wall construction.  

There is a HR owners web site just as there is a Monaco owners web site.  Hope this helps.

Chuck B 2004 Windsor

[CorinthWest]

On it, Chuck.  Thank you!

[CorinthWest]

Update:  The way I have it connected now, I have a 10mA parasitic draw when the disconnect if "off", and 30mA when it is "on", which is within spec.  However, the ignition in the coach is dead (dash is black and it won't crank) when it is "off", and starts normally when it is "on", as it should.

Edited February 28, 2022 by CorinthWest

[cbr046]

5 minutes ago, CorinthWest said:

Update:  The way I have it connected now, I have a 10mA parasitic draw when the disconnect if "off", and 30mA when it is "on", which is within spec.  However, the ignition in the coach is dead (dash is black and it won't crank) when it is "off", and starts normally when it is "on".

Sounds about right, but if you're OCD you can start disconnecting cables / devices in the off position just to know where that 10ma is going and is it critical. 

- bob

[CorinthWest]

Don't tempt me.  LOL

[W7BE_Bob]

I added full disconnect switches to both banks, negative post. Chassis switch is rated 3000A and house 300A. When they off the only drain is battery self discharge.

IMO the starter reprsents a very heavy draw and the + should go directly from the battery to the starter. But there are many variations by Monaco. 

The main criteria for me is will is start easily in sub freezing weather?

[Chuck B 2004 Windsor]

1 hour ago, W7BE_Bob said:

I added full disconnect switches to both banks, negative post. Chassis switch is rated 3000A and house 300A. When they off the only drain is battery self discharge.

IMO the starter reprsents a very heavy draw and the + should go directly from the battery to the starter. But there are many variations by Monaco. 

The main criteria for me is will is start easily in sub freezing weather?

IMO you do not put the disconnect switch on the negative post.  Put it on the positive post

Chuck B 2004 Windsor

[W7BE_Bob]

Just now, Chuck B 2004 Windsor said:

IMO you do not put the disconnect switch on the negative post.  Put it on the positive post

Chuck B 2004 Windsor

Electrically it makes no difference as the circuit is now either open or closed. From a safety standpoint with a positive post switch a wrench that connects from the postive post to ground is dangerous. This is the same reason why a car negative cable is removed first and installed last.

[Chuck B 2004 Windsor]

IMO, you have it backwards.  Chuck B 2004 Windsor

[Chuck B 2004 Windsor]

Called my local Auto Zone store.  They recommend removing the positive cable first.  Chuck B 2004 Windsor

[W7BE_Bob]

Google disconnect car battery.

Just now, Chuck B 2004 Windsor said:

Called my local Auto Zone store.  They recommend removing the positive cable first.  Chuck B 2004 Windsor

Don't take your car there.

[Chuck B 2004 Windsor]

Same for Walmart.  Both stores sell more batteries than all others combined.  Auto Zone has corporate written replacement procedures for all the products they sell because of liability issues.    Same for Advanced Auto, and the local NAPA parts store.  But, then it really does not matter is one is careful.

Chuck B 2004 Windsor

[Tom Wallis]

I've been a certified professional mechanic since 1971. Both training and experience taught me to remove the negative terminal first. If you touch your wrench to anything other than the positive post while removing the negative terminal nothing happens. If you start with the positive terminal and touch your wrench to any metal you'll be welding.

[DavidL]

On 3/2/2022 at 12:42 AM, Tom Wallis said:

I've been a certified professional mechanic since 1971. Both training and experience taught me to remove the negative terminal first. If you touch your wrench to anything other than the positive post while removing the negative terminal nothing happens. If you start with the positive terminal and touch your wrench to any metal you'll be welding.

Yes, I agree (and am also ASE Master Certified). And have done it positive first and have suffered those consequences.  Ain't pretty.  My ears are still ringing from the explosion.  Thankfully my shop has a full bathroom where I was able to flush the acid off my face, out of my eyes before any damage.  The explosion only takes seconds from grounding a battery positive.  Blows the whole top of the battery sky high.  The lead battery post landed on the ground several seconds later (that's how high).

I am assuming this is another Campfire tale of lore that goes around a lot as I don't see an electrical reason to remove the positive first.  Small possibility is if there are several negative cables and the teenie tiny one is removed last and then any current flowing wacks that small cable (highly unlikely).

But many folks say "my RV manual" or "my RV tech" or "my RV best buddy who knows everything" say to remove the positive first.  But there is never a technical reason stated.

And my long experience with Parts counterpersons is to take AutoZone information with a grain of salt.  If they really knew what they were talking about, they would be an "A" Tech at the local dealership making triple what they are making at AutoZone...Same thing (or moreso) with Service "Advisors" at dealerships.

And Google?  Any answer you can dream of is on Google.  Doesn't make them all right.

What you are stating makes perfect sense and why you remove negative first.  So I will try to do that whenever it's physically the best way.

 

There should be a forum thread discussing Tales of RV'ing Lore.

Candidates: How to disconnect a battery, How to level an RV (this one can get complicated), Should I hang my axle from the shocks...those are the topics that immediately come to mind.

Edited March 5, 2022 by DavidL