Ready for the APOCALYPSE? Army Truck!

Probably the most obscure and brutal vehicle that I have had to diagnose to date.
Meet the 1996 Stewart & Stevenson Light Military Tactical Vehicle (LMTV) #1078 4x4.
Owner accidentaly reversed the battery polarity and POOF got some major sparks.
Let's see if we can track down the problem, and get this BEAST back in service.
Enjoy!
Ivan

[@547Rick]

How can you not watch this repair? We all as kids played with army trucks. Thanks Ivan for sharing!

[@SuperM1687]

"Should be fool proof, its designed for Army use" lol

[@biggsdarklighter4586]

I am a 25yr mechanic, and not only was I fascinated by this, I actually learned something!

[@repairitdontreplaceit]

hi ivan those diodes are pressed in you can buy the diodes online . pry out that wodruf key and un do the wires bolted onto the diodes (mark up what wires go where ) and you can use a puller on the whole diode front plate . or just remove all the wires from the front plate and measure what diodes have failed and the pull them out

[@YDVDL]

Ivan,where is part 2...Иван давай продолжение...супер интерестно.. РЕСПЕКТ from Rochester NY

[@AntonBabiy]

EE here... scr is essentially a diode except you can control when it turns on but to turn it off it needs 0V potential between anode and cathode. If this alternator uses a single set of windings I'm guessing they use the scrs to only take the lower part of the sine waveform coming from the coils and is pretty clever.... but very noisy electrically wise. Your biggest problem will be getting the scrs out of the housing which on most alternators ive seen is potted. very likely only 1 or 2 are shorted if they're using them as a full 3 phase bridge so not all need replacing. just a word of caution, if you experiment with external replacements first fire it up with the 12v disconnected cause if the scr is on all the time it'll send 24v into 12v. some things I've simplified so feel free to ask details

[@davidhagan5353]

Brings back memories of working on my old deuce and a half with the multi fuel engine. Oh and 24 volts will nicely burn a chunk out of an errant wrench swifter than a rattlesnake...

[@supercalcium]

Watching Ivan, is much better than Netflix. I think the problem is not the alternator, lets wait for part 2

[@gmoney9588]

A special Gods blessing to you and your wife in these times of trial . Please stay healthy , strong and safe . God bless .

[@michaelferik8060]

That's what I like about this channel. Never know what the next video is going to be about for sure!

[@gcfixitc9283]

ditto

[@andrewvillanueva4222]

Awesome videos bro!!!! You and Eric O have the best car repair videos.

[@riblets1968]

When I was in the Army (late 80s, early 90s) the thought of a Russian working on one of our trucks was unthinkable! Things have changed for the better in this respect.

[@31terikennedy]

T-55:)

[@gonzgarr1592]

Ivan you seem to amaze me with your drive to fix anything stay save

[@fredflintstone8048]

If it turns out to be the scr, with any luck there will be a part number on the component that can help with getting some specs on it like PIV, current rating, etc. in case you cannot get the exact part you may be able to find a good substitute. SCRs are like a diode that's switched on with the gate signal, and then they are turned off by crossing the zero line in the sine wave. They must be triggered for each cycle .. They're used to control duty cycle by varying how far into the wave the gate is triggered on. For example if the gate is triggered on after a 90° delay in the wave, the duty cycle would be 50%. SCRs handle only one side of the wave. A triac is a double SCR which handles both the positive and negative going portions of a wave.

[@daveg6220]

Keep the the video's coming I got nothing better to do than watch you work!

[@ericcorse]

Looking forward to part two. Way cooler than a scissor lift.

[@jamesspash5561]

Military wiring is not always like you think. Postal vehicles the same. Years back a local guy bought an ex military dodge truck with and electrical issue. Previous owners had taken it around the area shops, and no one could deal with it. To the point all the local shops knew the truck and said no way that trucks got electrical issues. When it got to me, the issue was blowing the tail ight fuse intermittently. Long story short, on this unit the tail light fuse also feed the cigar lighter. The guy did not smoke, so the ash tray was full of change. A simple dime jiggling around in the empty cigar lighter socket removed repaired the issue.

[@cliffyb5896]

That hydraulic fluid that was used in those air/hydraulic systems was fire and explosion resistant but really bad for your skin and health. Glad you wore gloves working on that.

[@lylecheckeye6300]

AVE would have super glued the o-ring together :) LOL

[@lonwillis783]

Note the burned label LOL Thanks Ivan good job and stay safe.

[@kthwkr]

All us OEM guys are required to make everything reverse bat tolerant. Sometimes we use series diode. Sometimes backward diode in parallel with input. The idea being the large current will blow the fuse before any damage. I am surprised that even a circa '96 would get damage from reverse bat. We subject every component we make to reverse bat and double bat. Once when testing a new brand of diode I reverse bat a test unit more than 200 times. I blew 200 15A and 20A fuses. Observing the current on O'scope I saw sometimes as high as 250A for 100ms. Sometimes the fuse would do a double spike as the filament melted and then fell back across the internal contacts and conducted again. That was cool and unexpected. I guess this military tax payer vehicle is not designed as well as a low end GM vehicle.(and what's lower than that) And today I am writing a check for my taxes so they can buy more poor design quality crap.

[@dans_Learning_Curve]

Interesting input? Thanks!

[@tomvleeuwen]

Is that also true for the alternator? Because it won't be as simple as putting a diode in series - it would simply conduct since the alternator is supposed to dump current in that direction. A diode in parallel is basically something you already have in your bridge rectifier. So all you can do is add a fuse and make sure the bridge rectifier is significantly overdimensioned.. Any car I've seen that had the battery reversed had a broken bridge rectifier in the alternator and a few blown fuses, so all other components are protected exactly in the way you describe. Note that these were European cars. But the fact that the current flowing through the alternator is the normal direction when the battery is reversed makes it very hard to protect the alternator.

[@HUBBABUBBADOOPYDOOP]

This is quite interesting, thank you, Ivan!

[@baxrok2.]

Very interesting repair. Can't wait to see where those diodes live. Thanks Ivan!

[@rafflesnh]

Stay safe Ivan and thanks for keeping us entertained. (And informed!) :-D

[@UNEEK_LOGIK]

Damn Ivan bringing back memory’s from when I was in the service as a mechanic

[@PaulysAuto]

Awesome stuff Ivan! Good times on the M1078!

[@jamesh6229]

Military vehicles are always interesting, thanks for sharing Ivan.

[@gregory891]

Caterpillar 3116. 1.1 liter per cylinder x 6 = 6.6 liters I work for Caterpillar. From what I find, the engine was built, tested and shipped Feb 1996. I don't see the charging alternator in the factory as tested / build list - but don't give up. Try the local Caterpillar dealer, Cleveland Brothers. They will need the serial number and possibly engine arrangement number on the sticker on the valve cover.

[@robinsonsmotorcycleandauto3929]

Looks more like a Generator than a alternator. Also there is a cab lock when open to keep it from being able to come down. Interesting stuff to work on for sure. Cab overs are in my opinion more friendly to work on to access components. Pretty cool truck to own

[@wyattoneable]

This one has been interesting so far. You'll work on anything just for the fun of it. :)

[@mkilptrick]

Love the variety of equipment you are working on.

[@tmet01]

One of the best car repair videos I've seen. Thanks!

[@CubasAutomotive]

So interesting! I'm definitely following this project!

[@tomsmith29]

if anyone can fix it it has to be you Ivan ! can't wait for the repair

[@bobweiss8682]

SCR shouldn't be too big an issue to find. Commonly used in industrial gear like motor speed controls. NTE electronics has a broad line of replacement parts like that if you can find the original type number. Available from Newark, Digikey, Allied, Mouser, etc..

[@marknaravas318]

Bob Weiss indeed. I used scr’s and triac’s all day long in stage lighting to rebuild the dimmers. NTE should be able to source a new set of parts. There are probably/possibly numbers in the old ones that may help. Just make sure on the info for the part it can handle the amperage and voltage. And be sure there’s a heat sink involved.

[@iian0]

Thanks for another great video! Stay safe and well...

[@georgeswindolljr1980]

Awesome video young man, nice unexpected change of pace!!!!!!! Thank you for sharing!!!!!

[@bostedtap8399]

Great vlog Ivan, definitely something new on the PHAD channel. Stay safe all and thanks for sharing.

[@AMStationEngineer]

Ivan, use Chestnut Hill Auto Electric in Martindale, PA, near Denver, PA and US 222; they stock everything Cole Hersee, and have several thousand hard to find components in stock. Chestnut Hill rebuilds their own alternators, and by appointment, they'll do it immediately, and you can take. They do MCI Charter Motorcoaches all the time, and fire/EMS/police electrical repair's to. They're Mennonite, so no website. If you visit, let me know, I'm local, run a motel, have access to several restaurants which have great home cooked meals. and am fluent in Polish.... Slivovice??? Kolbasz, Halubki. Haluski, Sirets/Hrudka??, and a local brewery...

[@drewsdiagnostics7201]

The cool vehicles you get to work on! Looking forward to part 2.

[@jonathansandefur1026]

Great info, thanks for the time you invest to make these videos happen

[@Paul1958R]

Ivan, Great video and case study - I cant wait until part 2 to see you get that monster apart! God bless Paul (in MA)

[@alexgoldstein7997]

Cool video Ivan! I bet that thing will burn anything you put in the tank...what a monster!

[@tiredoldmechanic1791]

We ran the Niehoff brushless alternators in snowplow trucks. Try contacting them to find a local dealer. They made high quality ignition parts for many years but only make brushless alternators now. I think you replace the drive end housing.

[@georgeshadrick640]

thank you Ivan be safe

[@heretohear8662]

Stumbled upon your channel ...pretty cool!

[@robertevans6481]

I so hope there is part 2....very cool 🚚

[@MechanicTechnicianRepair]

Good diagnostic. Amigo nice video

[@marksplace]

Another great video from the man himself. Thank you sir and be safe my friend.

[@srnc9740]

The best idea is to tear it apart and see the code on SCR, which will be the military-grade and maybe you'll find the specs on the internet and replace it with an industrial-grade with same specs or better. It's gonna be a metal case for high amperage, which isn't cheap but at least affordable. In Europe, they are called thyristor, so this may increase the chances to find one It may be found in some welding machines, but not sure! Good luck and let us know how it's going!

[@adriaan9011]

well sometimes they call it a thyristor-module, a thyristor is a thyristor

[@carlosmoreira779]

Never saw one before! Thanks for sharing!

[@mzee5533]

Carlos Moreira ive worked one giant like that on a liebherr 9350 excavator but it was only 24V

[@billneu9520]

Our service members that are working through one of the worst times in our lives we all should THANK them. I am praying for a swift end to this virus. So, our live can return to normal. You Ivan and others that are making videos are part of the answer by keeping internet views entertained and happy. I am hoping that you and your family are staying and working SAFE. Thank you again BILL N LINY

[@chrisi1909]

You have Cars (Trucks) around - unbeliveable :) Great Video...

[@offroad-fan1805]

Wow, this truck looks VERY similar to the Austrian Steyr 12M18. The Steyr 12M18 is very popular in Europe for conversion to all-terrain motorhomes.

[@Vespastendert]

Offroad-Fan it has a Mercedes benz NG steering wheel

[@Blazer02LS]

Stewart Stevenson built them using the same design. They redesigned them to use different components like drivetrain and such. The US version has 225 hp and an automatic. They pop up in surplus auctions a LOT.

[@billneu9520]

Ivan, you repair some interesting vehicles and items for thousands of viewers for your and our entertainment. Thanks for your time keep them coming, we are stuck are home. Bill N LINY

[@pirihern9329]

Good luck with the alternator. Sweet video . Keeps my mind from going nuts ivan and family peace stay safe. Waiting patiently for the next video nowhere to go

[@arthurfricchione8119]

Ivan, you can definitely find the projects. This is a good one looking forward to part two. Stay safe. Here on Long Island not so good. Have family relations with it. Sucks anyway keep us posted Artie ❤️

[@danrandle65]

almost looks like a unimog. boy do i want one of those

[@danrandle65]

@canuckguy worried ya maybe, i drive a truck so ya i know what your saying.

[@danrandle65]

@canuckguy worried ya it definitely wouldn't be a daily driver for sure

[@mikefoehr235]

Watching you drive that thing got me thinking...it has the turning circle of a small planet. Great video. Truck looks like a UNIMOG. It was made for an apocalypse.

[@MikesSoftLemonade]

The old polarity reversal

[@dwoodog]

expensive mistake

[@BobPegram]

In the voice of Maxwell Smart!

[@pl5882]

Dam I want one of those! Maybe Santa will bring me one if he doesn’t die of COVID.

[@mrkttrdr2919]

u r capt marvel, cranes and army trucks are the challenges u meet head on. peety would be proud, good luck and be safe!

[@rrcoster]

One of most coolest machines you worked on so far....Always interesting see old military vehicles. Worst time for person accidentally mess up putting batteries in wrong lol. Sure wants to have it ready go with way economy going right now lol

[@PineHollowAutoDiagnostics]

He has two of them. He just wants to fix this one up and sell it :)

[@rrcoster]

@@PineHollowAutoDiagnostics Be perfect doomsday preppers vehicle lol

[@theadventuresofjavier8698]

Apocalypse be dammed,You have the Suzuki....nuff said😀

[@richardcranium5839]

neat setup similar to some of the delco's in that the rotor is energized via induction. also tnteresting the 12 and 24 v are two seperate stators. with only one rotor would explain why the use of scr"s. it would be interesting to see what uses 12v and what does 24 v as to why the logic in the dual system. older trucks used a series parallel switch and started on 24 but ran on 12 with a 24 v starter but 12 volt alternator

[@Toyotas_n__Tools]

Thats a slick craftsman man purse ;) lovin this video and rig! I had a spark plug wire melt on a header and it shorted out all sorts of things with the efi system that i just ended up putting a carburetor on and it'll run off of 3 wires now =)

[@cliffyb5896]

12 volts for regular lights, electronic transmission controls, CTIS, and the commercial 7 pin round trailer plug. 24 volts for starting, black out drive lights, and military trailer plug. Newer trucks have 12 volt engine and ABS computers too.

[@waxhyehen1702]

Tnks fr this adventure👌😎😎just epic.👍

[@mikeaho4143]

Very interesting. Kind of out of your comfort zone, but definately doable with some online info. Keep us updated as I'm really intrigued by something out of ordinary. Stay safe and healthy also.

[@AP9311]

Wow. That's so neat having to fix tje apocalypse truck lol. To coin the phrase, ready for the end of the world, Get that truck ready lol. Lmao!! Fun video. I die like that switching alt. That's something new to learn! Many thumbs up!!

[@45AMT]

Wow! That was awesome!

[@Monkeh616]

That alternator got roasty toasty, melted its own label off. Bad times.

[@nigelclark7360]

Good stuff

[@chickenoodlesoup4202]

Stay safe buddy love your channel

[@elpuerco6059]

Painful and expensive are important qualities in a lesson that typically ensures it will never be forgotten 😉

[@zx8401ztv]

Looks like stud diodes/scr's screwed into the front plate. Yep it's a beast alternator :-D, i thought diodes as well, a common death for reverse polarity.:-( Hope the regulator was not damaged :-( When i used to work at an auto electric repair factory there were alternators for buses that made you squeak when you picked one up lol. I used to repair the cast regulator boxes for them. The starter motors looked like torpedos, really heavy duty.

[@mala4076]

Great video as alwas.

[@daveellis8732]

Ivan, Niehoff is located in Evanston Ill. They may have what you need, Really like your thought process, I will keep watching ,Thank you for channel. Dave Ellis

[@somerandomguy3868]

At least you have a cool project to work on during the shutdown, that's some pricey alternator, looking forward to the fix

[@rfcarlson1]

You should be able to find the SCR on line -- either DigiKey, Mouser, or Newark will probably have it. I almost crapped when you pulled that puller off pulling on the pulley flanges. Experience has me using a bearing splitter to support the pulley from behind. Try and find a NSN number for the alternator. From that you can probably find the Army's alternator manual. That should have an exploded view in it.

[@PineHollowAutoDiagnostics]

All the pulleys are heavy steel... No chance of deformation with the baby puller haha

[@gorak9000]

I bet the diodes and SCRs are potted under that front cover where all the wires attach. I bet that comes off when you remove all the cables, and all you'll see is epoxy filled blobs. That would certainly make it more robust and vibration resistant in the field, but it's going to make the repair super fun. You can heat the epoxy with a heat gun and pick away at it though to get it out, but it's quite the chore.

[@willf5768]

My M1A1 Abrams needs a tune up oil change and track rotation 😃🤣

[@timothybarney7257]

Nothing like a vehicle that you have to remove the engine to change the oil. At least it was designed with that in mind and the process is pretty straightforward as compared to say an engine swap in a modern car which is nightmare in comparison.

[@cletusgaming6108]

@@timothybarney7257 if I was going to have to pull the engine just to change the oil I would set it up like the Navy did our small boats and put in a remote system in where I could pump oil out of the engine and replace using the same port just need to reverse the pump

[@timothybarney7257]

@@cletusgaming6108 I didn't design it, just know what needs to be done. I fact I think I wasn't quite a teen when it was designed.

[@scuba422123]

yea gotta get that fixed now....well you know just incase.... I bet he is packing some wild fire power also he can swing the cost of a new one but anyways I give you credit for getting involved in something like this

[@ScottDLR]

It was a good time to convert to 12VDC only. That is the common way to go in heavy equip.

[@robertoruiz7069]

Hi Ivan,when i heard you say {army use} i cracked up.Since i was in the army in 1972,it was spot on.Here's the ISSUE....to really be army proof it SHOULD have been designed with ONE OF THE POST SQUARE SHAPE!!!!!.They are both round..DUH. yes i know they're a little different in size,but a file ,sandpaper or a knife blade and it will fit,believe me....I'VE seen it happen.What's that you say IVAN??? they're RED and black colored???But i only have army green paint on the shelf,when you said to paint them for protection against corrosion.SO i did,you didn't specify..RED for positive and BLACK for negative....hey I'M ONLY A PRIVATE,haha

[@WilliamPetefish]

LMTV A0... should have a CAT 3116 engine. It uses a Neihoff dual voltage alternator. I think I have the TMs somewhere for this one. It may be a M1078 or some variant there of. MME sells some upgrades for it that do a really nice job.

[@carlm2590]

Keep pumping until you get the desired outcome 😀

[@jeremystone6613]

look after yourself buddy. Looking forward to the degutting of this one!

[@dave468024]

That is way too cool!! I am subscribed to a another KZbin channel that is rebuilding something similar to that kind of army truck.

[@steveorshon]

I'm convinced if anyone can fix it, it would be Ivan. Waiting patiently for part 2.

[@fieldsofomagh]

Only a matter of time before we get to work on a Sherman tank. That is one gigantic alternator. Seems dual purpose charging the 14 and 28v batteries. The scrs might be sourced individually and replaced with some Russian ingenuity. Luckily that's all that was blown. Hard to know where to begin to disassemble the monster. Pricey new ones not to be sneezed at. Good luck with the tear down and keep safe. Please God this plague will pass over soon and summer will bring better tidings.

[@binnsh]

Up here in Rochester ny, I take things like this to Pro Rebuilders, great shop.

[@rickeyburke2596]

Theres alot you got to learn about the LMTV's

[@CumminsDriver100]

Well that damn alternator is bigger than some of the three phase motors I deal with at work as an industrial electrician!! Might as well be a Lambo, because as they say, its all Greek to me! As far as military vehicles go.

[@DanielSan014]

Well I just hope that it wasn't as bad as me shorting the positive terminal to the chassis and a battery blowing up. Wasn't terrible, just blew a hole in the battery, no fluid lost, battery still works.

[@billsimpson604]

Way back in the 1960's, a fellow drove his Corvette into a tire shop my father was managing near New Orleans. The battery had blown up inside the car. We cleaned up the acid as best we could, installed a new battery, and he was on his way in about an hour. Until then, I think nobody there had even seen a battery inside the car.

[@RJ-vb7gh]

It's been a whole lot of years since I rebuilt my last alternator on my 1966 Olds. It had diodes as best I recall. But I"m thinking my 1973/1976 Buick had a "rectifier chip". In any case the windings were cooked so I just bought another alternator from the local rebuild shop... I'm guessing the part you need would likely cross reference to one from a common alternator from the same vintage. If I was paying close enough attention, you are in the 12 V circuit so why design and produce a specialty part when there would have been plenty available on the shelf. Good luck.

[@charlesmiller5078]

I need to get to welding those knives onto my wheels, and get my steel window plate fitted. Gonna be mad max here we go, just going to wal mart to get some butt wipes. Ivan has a 99.9 % success rate going into this, lets see if he can keep that success rate up there. Go Ivan, Go Ivan.

[@for2utube]

If you think it was heavy to get out, wait until you put it back in!

[@j.j.springer1099]

worked with SCR 440 volt AC3 phase to 500 volt dc think backwards and you can pick the bad SCR, otherwise you replace the wrong one every time

[@jkbrown5496]

I'd never heard of phase controlled bridge rectifiers, but that is apparently what it's called when you use SCRs. I wonder if it is the firing control circuitry that the reverse polarity blew? It will be interesting to see what you find.