Volvo Penta MDI (Black Box) failures

[mlibkind]

Thank you for info on accessing the terminal posts. When I replace the box next week I’m sure to see this.

[double u]

Could anybody be please more specific about where they wire up/connect start-switches that circumvent the electronics? Does the alternator charge then?
Right now we are having friends in Bora Bora with a D2-55 failing to start/ charge because of either Blackbox or instrument panel failure

[HighTemp]

The connection on an MDI is made between the battery and the start posts on the back side of the MDI. The push button switch is in between, so when the button is pressed, 12V from the battery is momentarily applied to the starter, thus turning the engine over. Once the button is released, 12V should no longer applied to the starter motor. This should have no effect on the alternators ability to charge the battery if everything is wired properly.

[mlibkind]

I just recently did this in order to start the engine to move my boat to where I could get a mechanic to work on the engine. I purchased a remote start switch from an auto parts store for about $16 and it had alligator clips on it. I removed the black box but I later learned that you don't need to remove the wires from the box to use the remote start switch. To shut the engine down you use the yellow emergency stop lever.

[Dsanduril]

The MDI has three multiconductor cables/harnesses attached - ignore these. It also has three wires attached at the end nearest the shaft; red/yellow (start, closest to block), red (+12V, center), and orange (glowplugs, furthest from block).

A momentary switch from red to orange will run the glowplugs. Likely not needed in the tropics. Note that this switch would carry the full 40A current that runs for the first several seconds until the glowplugs get warm, so switch should be substantial.

A momentary switch from red/yellow to red will start the engine. This only fires the solenoid, so just about any switch will do. Or go old-school and use a screwdriver on the terminals at the bottom of the MDI. I got quite adept at this and it worked fine before installing a switch.

[ramblinrod]

Originally Posted by HighTemp

I do have a "somewhat" sympathetic understanding of what VP is trying to do. They have to satisfy all of us who have their engines in our boats as well as to rectify the problem moving forward. It is not an inexpensive proposition and they are already up to the 5th or 6th generation MDI, so there has been multiple attempts to correct the issue.. VP is following a prudent course of action, but to date, it has fallen well short.
At least in my personal experience.

The switch thing is a fine back up, but a permanent solution needs to be found and implemented. Hopefully this latest generation of MDI's will be the last generation of MDI's.

I too have some sympathy for the pains VP is going through. It is a common problem /issue in product design.

A company hired engineering grads expecting them to know everything day one.

It simply doesn’t work that way.

A piece of parchment indicates that you can learn new things.

A history of successful product development, indicates that you can apply common sense.

Book smarts alone doesn’t cut it,

Today, a lot of companies are trying to scoop the latest grads because they will work for cheap, crazy hours, no vacation, no pension, no benefits.

There needs to be one or two old-timers on every design team, to teach the young-uns old school common sense.

One of the last design teams I led, I assigned a green mechanical designer and procurement specialist to come up with a series of SS disc orifices to produce a specific CV for water flow. I gave them the O.D. and I.D.s.

After several weekly team meetings, they didn’t have a solution.

It took two months and they came with a procurement estimate of $25 avg. for custom fabricated SS disc orifices.

At that meeting I asked a senior procurement specialist to take the same info I provided at the onset and call McMaster Carr.

The next day he had a list of off-the-shelf SS washers that met spec at avg. $0.05 each.

The exercise taught the greenhorns, before you turn on the computer, and demonstrate your skills in the latest 3D modelling software, stop and think about what the desired end result is, and the fastest, cheapest, most reliable way to get there.

I have countless stories of similar botched product development activities.

I have worked for companies with high functioning product development teams, others not so much, and others where all effort was placed on trying to protect the corporate brand from total internal dysfunction.

The fortunate thing is that one doesn’t have to work around over abundant egos in the engineering field. LOL.

[mlibkind]

Simple is better

I enjoyed reading your post about engineering. I'm a retired mechanical engineer. I worked my last several years on a project that operated at 40 Kelvin, ultra high vacuum (that was the reason for the cryo temp), and had tolerances on the order of 3 microns at temperature. While manufacturing techniques for the hardware were state of the art, the design was by necessity simple. Complex would have created extreme problems with meeting vacuum and dimensional requirements.

[CarinaPDX]

While pursuing an alternator regulator for the V-P D2-40 I was communicating with Eric at Nordkyn Design about his product (VRC-200 Reference Controller, which I bought and recommend). He had moved his black box off the engine for reduced heat and vibration, and therefore higher longevity. Apparently if one cuts loose the wiring to the MDI there is enough cable length to mount it a short distance off.

Greg

[rayzickrick]

Originally Posted by kipwrite

I can confirm that it’s fairly easy to install a simple push button start that allows my d2-75 to run independent of the MDI. The stop lever works nicely in conjunction.

If you run the engine this way the panel does not register engine hours and there are no alarms, nor does the engine room fan operate, and this bypasses the glow plugs, so this practice is not without risks. That said, I find this solution perfect when my MDI decides to fail at a bad moment.

I’m on my second MDI at about 950 hours. The serial number is 22458451 P W 1738. So far this one is holding up.

My original MDI failed at 600 hours, by intermittent start failures and numerous random engine shut downs. You can unplug the stop selonoid to prevent these shut downs from happening, though this will trigger an alarm.

All in all these MDIs are horrible, and in my opinion dangerous.

I can’t believe Volvo hasn’t addressed this openly, with a well publicized recall and a better engineered solution for everyone with MDI equipped engines. Unreal.

Your parts serial # is dangerously close to mine that just failed yesterday. Mine is 22458451 W1638. I guess the only good thing about my failure was, I was at my slip at that time. For so many failed MDI's and just now hearing about this not good. I guess Monday I'll be on the phone with VP USA.

Ray Zickrick

[kipwrite]

Originally Posted by rayzickrick

Your parts serial # is dangerously close to mine that just failed yesterday. Mine is 22458451 W1638. I guess the only good thing about my failure was, I was at my slip at that time. For so many failed MDI's and just now hearing about this not good. I guess Monday I'll be on the phone with VP USA.

Ray Zickrick

Thanks.
That MDI was replaced by Volvo under the recall. The latest one is holding up.

[SweareDeep]

The part number from V-P for the replacement under the recall is 23231607.

However, at least from my experience in the US, while the blue box that V-P ships the MDI in is marked on the outside as 23231607, inside the box is part number 23195776, an earlier part number that is prone to failure.

[rayzickrick]

Originally Posted by kipwrite

I can confirm that it’s fairly easy to install a simple push button start that allows my d2-75 to run independent of the MDI. The stop lever works nicely in conjunction.

If you run the engine this way the panel does not register engine hours and there are no alarms, nor does the engine room fan operate, and this bypasses the glow plugs, so this practice is not without risks. That said, I find this solution perfect when my MDI decides to fail at a bad moment.

I’m on my second MDI at about 950 hours. The serial number is 22458451 P W 1738. So far this one is holding up.

My original MDI failed at 600 hours, by intermittent start failures and numerous random engine shut downs. You can unplug the stop selonoid to prevent these shut downs from happening, though this will trigger an alarm.

All in all these MDIs are horrible, and in my opinion dangerous.

I can’t believe Volvo hasn’t addressed this openly, with a well publicized recall and a better engineered solution for everyone with MDI equipped engines. Unreal.

If it is indeed the engine heat that could be causing these MDI's to fail. When VP sends me a new one prior to mounting it I will place a small 1/4" piece of cork behind the MDI to help isolate it from engine heat. Can't hurt. Right? I have also ordered a remote starter switch with alligator clips so I can at least get the engine started and not be stranded on Lake Superior somewhere.

[rayzickrick]

Originally Posted by CarinaPDX

I thought I'd resurrect this old thread in hopes it will help others. I have a very old version of the MDI, haven't commissioned the engine yet, and have watched as others have had unending problems. I was just thinking about buying the 5th version of the MDI (#22594274) on fleaBay for $300 (less than half price). It turns out that Volvo-Penta has finally (!!!) addressed the problem by issuing a Service Bulletin that offers free replacement for some MDIs - with a NEW, 6th version (#23231607). It turns out that the 5th version won't start the engine if the battery voltage sags. Other versions have different problems, with the first version including electrolytic capacitors which fail due to the engine heat. For the record, here is the history of part numbers:

21120710 > 21120871 > 21511215 > 21558939 > 22594274 > 23231607


This is a sorry tale...

Greg

Attachment 178954

Hello, so from this part #22458451 (mine) that failed Friday. Would you say that mine was a Gen. 5 MDI? I have smelled enough burnt electronics to know... mine smelled burnt. Thanks. Ray Z.

[CarinaPDX]

I don't know - it is not on the progression that I had, and I haven't been able to find the french blog that had the info (and might have been updated). I suspect that it may be an even newer version (7?). When you get the new MDI you should try mounting it completely off of the engine. As I posted above, I was told that there is enough cable to allow moving it a short distance. It looks to me like the protective rubber shielding might have to be cut to do it, but inside there is enough wire to move it some distance. Even with dampeners/insulators I would not leave it on the engine.

The tale gets even more sorry...

Greg

[rayzickrick]

Ok. Thanks. @CarinaPDX