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A0, A1, A1R and TM's
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Ronmar
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Looks like a C7 to me… Whats the dash look like? If it has the integrated/bussed gauges, you air pressure gauge issue just became a little more involved, as those sensors are soldered onto the board in the gauge controller module…
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Oh! Oh! Oh! I know this one.
99% likelihood the MMDC (Medallion Marine Data Concentrator) pressure transducer for the gauge is dead. Medallion made the mistake of putting the transducer inside the unit. But it can be repaired if you can locate a replacement transducer or harvest one from an ebay MMDC, etc. Every MMDC I have purchased has had one dead pressure transducer - Medallion and S&S/BAE didn't filter the air going into them and they get damaged from moisture and debris.
Here's the inside of the MMDC. You have to heat and pry the back off it's glue. It's VERY strong sealant:
The red arrows indicate the pressure transducers.
The board is secured into the case with some REALLY aggressive potting compound that's essentially impossible to remove. So I just snipped the legs close to the board of good transducer from a donor and soldered it to the legs still anchored to the board where I clipped off the bad transducer. This worked perfectly. I have not had any luck sourcing any of these Honeywell SX150D transducers and new replacements do not have the exact same specs so they would alter the readings at best...... so my solution was to find donor MMDC's for now.
To prevent future problems (and I haven't had any), I installed inline desiccant filter driers before the MMDC to filter and dry the air and hopefully prevent damage to the delicate transducers:
99% likelihood the MMDC (Medallion Marine Data Concentrator) pressure transducer for the gauge is dead. Medallion made the mistake of putting the transducer inside the unit. But it can be repaired if you can locate a replacement transducer or harvest one from an ebay MMDC, etc. Every MMDC I have purchased has had one dead pressure transducer - Medallion and S&S/BAE didn't filter the air going into them and they get damaged from moisture and debris.
Here's the inside of the MMDC. You have to heat and pry the back off it's glue. It's VERY strong sealant:
The red arrows indicate the pressure transducers.
The board is secured into the case with some REALLY aggressive potting compound that's essentially impossible to remove. So I just snipped the legs close to the board of good transducer from a donor and soldered it to the legs still anchored to the board where I clipped off the bad transducer. This worked perfectly. I have not had any luck sourcing any of these Honeywell SX150D transducers and new replacements do not have the exact same specs so they would alter the readings at best...... so my solution was to find donor MMDC's for now.
To prevent future problems (and I haven't had any), I installed inline desiccant filter driers before the MMDC to filter and dry the air and hopefully prevent damage to the delicate transducers:
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And yeah, that's a C7. Same FML family as my 2008 just a much lower serial number:
Johno176
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I had a wonky gauge reading on one of my tanks and replaced the MMDC with a new one and the gauge continues go from reading correctly to dropping to about half of what the other one is reading. Happens randomly. I'm going to add the filters. Good idea. Any idea on the cause of the same gauge problem even after replacing the MMDC?
I will snap some pics tomorrow.
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You installed a BRAND NEW MMDC? Or a "good" used one? I have not experienced what you describe. I would swap the air lines and see if the other gauge acts similarly to rule out some kind of supply pressure issue to the unit. If it stays with the same gauge after swapping the air lines front to back I would say you have a second bad MMDC. Every unit I have bought "surplus" has exhibited the same transducer failure issue. One of them legitimately had 35 miles on it and already had a bad transducer. These trucks sit and the air systems don't get drained leading to rust and moisture and any of that gets into the transducers and it kills them. Very poor design IMO that didn't account for the conditions these trucks experience in the real world.
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https://www.mouser.com/ProductDetail/Honeywell/NSCSSNN150PDUNV?qs=C%2F0tY%2F%2FqZe9ewEwKCB2V2A%3D%3D
This seems to be the replacement recommended by Honeywell for that deprecated pressure sensor. From what I can ascertain from the DataSheets, looks to be compatible?
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You need to understand that the word "Classified" is not used in the normal way here. The info is not classified due to national security, (in 99% of the time) its a matter of the manufacturer not wanting to provide info to people like you. You are not in the military. You would be getting something for nothing. They spent millions on the design, and testing of the equipment. They provide the info in a manner specified by the military. It all cost big bucks. So why give it to you? No one is obligated to give you anything for free. If you want to get the TM's released for public use, then send a letter to the controlling Command, and request it. Few if anyone in the forum have ever done that. It might help if several hundred folks did that. Or write to the people of congress. Cant hurt.
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The last place to look for the Changes, is the cover page. Back in the OLD days, when we received changes to a TM, the change came with a new cover. Someone then decided that was a waste of money, and when you consider the millions of changes were printed and sent out, yes it saved money. So what we were supposed to do is insert the changes, and then write in ink, on the cover, "Change #2, added 24.Nov. 1977". Then when change #3 came along, that would be written below. So everyone could see what changes were applied to the TM.
*note that the cover page is the same as others but mentions the August 2005 amendments (I don't recall finding that amendment on any of the uploads here but it may or may not exist here on SS)
Thats why you may not have seen if a TM has been updated. Often when a digital copy was updated, the cover page was not changed. ALWAYS, scroll through the first few pages, until the TOC, to see if there are change pages listed.
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This is a picture, I think, taken in Graf, here in Germany. I drove by the MP the other day and saw several of them being used for training.
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They should work fine with almost any version.
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TM's for the A1 and A1R are slowly getting out to the public regardless of authorization or classification. ETMs are a pain to work so in the mean time networking is key. Find yourself a good warrant and buy him some BBQ.
Sound advive! Mostly, people just strip the PDF's from the ETM's anyway. You only really need them. The rest of the ETM is not a must have thing, unless you have LOTS of ETM's.
Sound advive! Mostly, people just strip the PDF's from the ETM's anyway. You only really need them. The rest of the ETM is not a must have thing, unless you have LOTS of ETM's.
Ronmar
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Yea, those look like the digital gauges, look for the MMDC box under the drivers dash, about eye level while standing on the ground when you open the door. Like In Generals pics, has 2 small airlines running to it. I suspect your power panel has 4 black modular relay/fuse boxes inside it. A1 variants notwithstanding, I believe you now posses what most would consider an A1R… R stands for Race, or “R” your pockets deep enough… Congratulations
I am no Einsten but conjecturing why any bafoon either in controlling Command or Congress would choose not to declassify vehicle technical manuals they regularly auction to the public is beyond me but; I kind of got the sense that it ain't because of national security.. As far as something for nothing, I bet there are plenty of people that would pay and the for profit corporations would oblige if they could turn a buck and not get into trouble.
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If it keeps acting up could we contemplate to bypass the circuit board transducers and install a simple in line pressure switch that would feed the alarm buzzer?
coachgeo
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there are two or three main threads in here on how folk made their own own Manual CTIS control boxes. Ron's are the most recent.
think the main key word to include in your search to find them is "Manual"
these are the ones I've bookmarked
CTIS and Arduino
Are you still selling these Christian? Hello! Yes, I just finished 2 for a M1088 and M1078 I think... Christian
www.steelsoldiers.com
Manual CTIS Conversion for M-1078
After severals request to start a post on this topic, I'm going to give it a try. I purchased my M-1078 in December with the control box missing from the cab. After reading several posts on the CTIS, and learning there is a lot of people having trouble with them, I decided to go the manual...
www.steelsoldiers.com
Manual CTIS, electric over pneumatic.
Ok, so my CTIS ECU is a brick with 5 solid lights and if I spend too much more on this project my wife will probably bury me in it:) That being said, I am also a bit of a control freak so I am converting to manual CTIS. I have looked at the valve and regulator method but decided to go about it...
www.steelsoldiers.com
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