M1078 Alternator Problem

[mechanicjim]

Not Arduino but yes all the new voltage regulators use solid state electronics to control things ....also adds to the cost of the things.

And for why not just tap the batteries......see original HMMWV all 28v...then they got an electronic transmission (14v) taped rear battery and found that it causes imbalance issues on 28v side. Lower battery never getting to full changed and draws down system. solution tap 14v from alternator to top up that lower battery and keep it charged. and now that the military has that the run with it they buy the cheaper option for every part they can 28v starter 14v lights etc.

also yes there's actually a MIL Standard for batteries less operation, its like 30min or so I don't know for certain. and think not of if it was jumped but as "Hey the battery box got hit with incoming fire and the batteries are gone does the truck still run long enough to get out of town".

 

[Suprman]

You can do a 24v alternator and use a 100a battery equalizer to run the 12v. Plenty of commercial vehicles do this. You cant just run a 24v alt and draw off 12v between the two batteries it causes battery issues over time.

 

[DOUBLE ALT]

Hello
If you send me some info and pictures of the mounting, I can help you.
LMTV problem is common. 12 and 24 volt ? 843 756 7007 RON

 

[1951M1078]

The reason for looking into this is ,what will happen when all the old stock is used up .

 

[Suprman]

The alternators are still current use. The military is not rushing to get rid of the stuff. Parts are scarce but can be found. It is possible to order direct from Niehoff. Expensive and I believe you have to get gov permission to buy the stuff.

 

[DOUBLE ALT]

The LMTV is only a 24/28 volt alternator with 100 amps. It uses S.C.R. (diodes) to convert 28 volts to 14 volts. You only have one 28 volt gauge-correct? The regulator has to control both the 28 volts normal and then 14 volts in the background. It is a inverter/converter.
Big problem, when you use the 14 volts, it takes the amps/watts away from the 28 volt side.
When you convert from 28 to 14 it takes about 20-30% more power/watts causing more heat.
It is a poor designed electrical system. More info 843 756 7007

 

[1951M1078]

Still no luck with the cheep Ebay regulator. Still no volts. Will retest the system tomorrow. Been using the Niehoff test's. Is their a better test in the TM's ? What TM and what page ? I'm kind of lost trying to find it.

Been think of going with the Heidebrink system ? Why stay with a Military system if new parts are high and hard to get when in the field ?

 

[1951M1078]

Well got a full refund. But still need to decide to repair or replace ?

 

[Suprman]

Did you try running a new excite wire?

 

[DOUBLE ALT]

Just so you know. We have gone through the expense and engineering to get 2 patents on our Alternators.
You can look them up to see why our units are more reliable than the other brands. Patents 9793779 and 7291933.
We only sell new, no used alternator parts. Go to the classifieds for our contact info.

 

[NDT]

See post #39, if you can't find the Niehoff parts, or are not convinced about a civilian option, go with the readily available HMMWV units.

 

[1951M1078]

Yes Will. Took power from bottom fuel valve stud (24V) still no LED's. I will go and redo the tests today to be sure I did not miss something. Battery's have been on the charger overnight just in case. If it fails the test again then I need to decide to replace the system with 'Double Alt' or just a regulator ? Still kind of upset about not being able to get new parts easy and at a fair price. This is not pointed a you Will.

Been reading in the TM 9-2320-365-20-1 page 2-1016.8 . Really this is a test ? Try it with a known good Regulator ? If I had a "known good Regulator" it would be working. The service truck must have a lot of parts on it?

 

[aleigh]

The LMTV is only a 24/28 volt alternator with 100 amps.

Not necessarily. There was a 200A option, which mine has.

 

[Suprman]

I have an extra 200a lmtv alternator. But not the whole install kit. It does use a different pulley and I think one tab mount is slightly different.

 

[aleigh]

I have an extra 200a lmtv alternator. But not the whole install kit. It does use a different pulley and I think one tab mount is slightly different.

That's interesting. About the pulley, mine seems to use the original belts. I got to replace them when I had my problems and used the part # off the spreadsheet.

 

[Suprman]

I think the belts are the same. I did the 200a on my truck a few years ago. I remember the 200a kit came with a pulley.

 

[chief Day]

Hey guys im a Chief of a fire department and we was given a M1078 and im looking for a voltage regulator part# 76761-3207 dual voltage so let me tell u the problem im having when we put or fire department radio in it and turned it on we get all kinds of static on it while the truck is running but u turn the truck off u can transmit and receive just fine can anyone help with this

 

[Suprman]

On the regulator there are 2 terminal posts. Is the back one marked ac and is there a wire going to it?

 

[chief Day]

Yes its marked ac and yes the is a wire going to it

 

[Suprman]

That’s an ac output. Used for driving a tach. Disconnect the wire. If you have ac on your dc power to your radio that would cause noise. I would check all of the grounds at alternator, batteries and frame to cab. That’s behind the grill on the passenger side.