The Mutts kicking my butt

[muttguru]

I had a look at the 20-1-1 Change-3 (1988) to check out the grounding wire connection to the instrument panel.
It's there !
The change-3 shows it as item 7 on page 5-144. It connects to the harness at wire no.57 (ground connection).
Ken

[glcaines]

My A2 has the grounding wire from the harness to a screw in the instrument panel. I believe my A2 is a 1977 model.

[ODRotorHead]

Thank you all for the information regarding instrument panel grounding.

Don't know if anyone might be interested in having this illustration, but it's a decluttered version of of the A2 wiring harnesses with both (front and rear) harnesses on one page. The M151 electrical system is about as simple as it gets but, as a new guy, it took me a little while to figure things out. These wiring harness illustrations were a help.


REMOVED - INFORMATION MOVED TO POST TITLED Miscellaneous Diagrams and Illustrations.


Let me know if you have any suggestions as to how I can improve it.

[ODRotorHead]

When I first got my MUTT I couldn't find a simple diagram of the battery box to confirm that it was in the correct configuration. I found this on the interweb, but it wasn't much help with regard to cable routing:

Battery Connections 001.jpg

It's too cold and damp to work outside and I'm tired of playing solitaire, so I made up these sketches In the hope that other newbies like me (and those to come) might find them helpful. If anyone sees a mistake, please let me know right away so I can make corrections (there's a note on the second sketch).

M151 Battery Box Configuration 00A.jpg

This one is after installation of the battery upgrade kit:

M151 Battery Box Configuration 00B.jpg

You may have noticed the somewhat odd organization of the cables and clamps in the second sketch. The rubber covers are all the same - covers offset to the right - so you have to get a little creative when you install the cables and clamps.

M151 Battery Terminal Covers 001A.jpg

The battery upgrade kit provides two significant safety benefits. It gets all of the extraneous cables - slave receptacle, comm gear, accessories, etc. - off the top of the batteries, and the larger covers provide much better insulation from accidental contact.

Mark

[Horst]

Your work is highly appreciated! Definitely stored everything so far for any future troubleshooting

[FoxMike]

Yes, thanks @ODRotorHead for your work getting this diagrams cleaned up (and everyone else for the additions)! This is very helpful for all of us.

[Mark]

The TM shows how to do it.I'll look for the picture.

[rickf]

The TM shows how to do it.I'll look for the picture.

were you answering the post on the other thread?
viewtopic.php?t=13742

[ODRotorHead]

Just a few electrical/lighting odds and ends . . .


REMOVED - INFORMATION MOVED TO POST TITLED Miscellaneous Diagrams and Illustrations.

[Mark]

Yes to rickf, I clicked on the reply to it

[Mark]

24 volt Connections.png

[rickf]

Mark, Something to note here on your pic, using two mismatched batteries like that will cause problems due to the different capacities of each battery. What will happen is the smaller battery will drain faster than the larger one and create an imbalance. When charging with 28 volts across the batteries the lower charge battery will be getting a full charge and the one with the higher charge will be getting overcharged. The voltage regulator only sees total voltage across both batteries and if they are not equal one of them is going to suffer. That is also why you never hook up a 12 volt accessory to one battery, always use a 24 volt to 12 converter.

[ODRotorHead]

This setup is the same, . . . only different:

M151 Battery Configuration Low 001.jpg

Positive terminal and negative ground after installation of the Battery Upgrade Kit:

M151 Battery Upgrade Terminal Low 001.jpg

Optional terminal insulation:

1.) Battery Upgrade Kit terminal cover.
2.) Insulating pad under the terminal.
3.) Five coats of electrical insulating spray on the after-market battery hold down (thanks Phil).

M151 Positive Battery Terminal Low 001.jpg

The same, . . . only different.

The other "Mark"

[ODRotorHead]

Since Rick mentioned a couple of concerns related to battery charging, I'll offer an additional perspective. I can't claim any expertise, but I did consult an expert in the field. Please note . . . this is not an endorsement of this charger, or this brand. I removed all text references to the manufacturer and the charger model.

I've read a number of posts about MV battery charging - here, G503, Steel Soldiers, etc. - and there are lots of ways to go about it. I'll describe the approach recommended to me, not because it's the best ever, but just to add one more option to the mix.

Background . . .
About twelve years ago, I was having difficulty keeping my M35A2 batteries charged (two trucks - long story). By coincidence, my next door neighbor happened to be an electrical engineer who worked for a well known marine electronics manufacturer. His specialty was designing the circuitry for marine battery charging systems right down to every transistor and diode on the boards. After explaining my problem and showing him the configuration of the battery boxes, he recommended a system that he had recently designed.

He had just finished bench testing and documenting one of the first production units (manufactured in Taiwan), so he had a tear-down unit that couldn't be re-boxed and sold. It was in good working order (fully tested!), but since he had no further use for it, he gave it to me gratis. It was a lucky break and the only thing I had to do was replace the ring terminals with clamps. I was in business.

I used the charger with my my M35A2 trucks for at least eleven years and now I'm using it for the MUTT. This is how it looks when it's set up:

Battery Charging for 24V System Low 001.jpg

I have no expertise in this subject area, but I really like this type of charger. Here's some relevant information from the manual:

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Overview

[Charger’s] Sequential Multi-Stage Charging process delivers three sequenced modes of operation that include: Charging, Conditioning, and Maintenance of each battery. This process is proven to extend the life of your batteries and will fully charge your batteries each time.

[Charger’s] Heavy Duty extruded aluminum housing delivers increased power and performance while providing improved durability and heat transfer.

The [charger’s] Distributed-On-Demand™ Charging Technology will automatically sense and distribute 100% of the available charging amp output, 8,12,or 20 amps (model specific) to any one battery or combination of all batteries. Each battery charger output is fully isolated.
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General Operation

With your [charger] plugged in properly, it will automatically / fully charge your batteries while it conditions and extends the life of your batteries. When you’re not at home, always leave your charger plugged in to reduce sulfate build-up allowing your batteries to be fully charged and maintained.

For long term or winter storage/ maintenance of batteries, [manufacturer] recommends that every 30 days: AC Power is removed by unplugging your extension cord at the GFCI outlet first, check battery electrolyte levels. Re-apply AC power to your Charger. This practice will properly maintain your batteries resulting in extended Battery Life and Use.
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Sequential Multi-Stage Charging Overview

The Sequential Multi-Stage Charging process delivers three sequenced modes of operation that include: Charging, Conditioning and Maintenance of each battery. This process is proven to extend the life of your batteries and will fully charge your batteries each time.

Stage 1: Charging
During this mode, the [charger] will use its available charging amps (as controlled by temperature) until battery voltage is raised to 14.6 VDC (Factory setting for standard Flooded (Lead-acid) / AGM batteries).

Stage 2: Conditioning
The [charger] will hold batteries at 14.6 VDC (Factory setting for Flooded (Lead-acid) / AGM batteries) providing a 100% charge to each battery, while conditioning batteries by desulfating each battery. Upon completion, the [Charger] will go to into its maintenance mode.

Stage 3: Ready / Maintenance Mode
During this mode, the Red Charging LED and the RED Battery Type LED (Factory set charge profile for standard Flooded (Lead-acid / AGM Batteries) will turn off indicating the Charge Process is completed, followed by the Green READY LED turning On.

The Green READY LED and the Blue AC POWER LED will remain on indicating that your batteries are fully charged and are being maintained with a precision 13.4 Volts DC Finishing Voltage (Factory set charge profile for standard Flooded (Lead-acid / AGM Batteries). [Charger’s] Ready/Maintenance Mode is perfect for short or long term storage and will never overcharge your batteries.
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There are lots of different charging configurations available. The configuration I'm using is the same as that recommended for trolling motor batteries (12V X 2).

ProMariner - 2 Battery - 24V - 001.jpg

Normally this system would be permanently installed with ring terminals attached to the batteries, Since I use it with three different MVs, using standard terminal clamps has worked well. Four clamps can get a little confusing, so I devised a way to label the clamps in order to avoid crisscrossing the cables. Side note - in marine wire color coding, the primary use of yellow is for ground.

Battery Charging Clamps 24V Low 001.jpg

I have a tendency to screw things up on a regular basis, so in an effort to out-wit myself (not an easy task), I made up a simple diagram for each type of vehicle. This is the one for the MUTT:

M151 24V Charger Configuration Low - 002.jpg

As I mentioned at the beginning of this long post (I apologize for the length) I am in no way endorsing this brand or model of charger. Based on more than twelve years of experience though, I do feel comfortable recommending this TYPE of charger. The batteries are charged simultaneously but independently, and balance is maintained.

Mark

[rickf]

Nice, And that last diagram shows exactly how I charge both of my batteries at once using two chargers, one for each battery. One question, if a battery is dead, as in 5 volts dead with that charger still charge it or will it default to a "bad battery" setting? All of the modern chargers I have used that are computer controlled will not charge a dead battery, they test it and call it dead. Then I go to my old standby transformer chargers with plain old school tech that does the same thing and plug them in for a few days and they charge the batteries up to a full charge. A lot of the time the battery will work for a couple more years. I have an old Battery Tender that weighs probably 40 lbs. and has dual output and multistage charging. I don't use it much because the first stage is pretty hot and it has heated up a couple batteries far too much. Next time I am out in the garage I will get a pic of it.