M 998 Regulator and Overall advice

[92'M998]

Hi - The info I received in my previous thread about bulbs burning out was very helpful . Her is the sitrep so far:

1. Voltage meter went from yellow, green and to red.
2. Both batteries were dead, and wipers very slow, bulbs in tail lights, etc gone.
3. Put batteries on charger at 2 amps for 18 hrs, no results.
4. Have a 60 am generator and have found a regulator on Eastern Surplus.
5. There were two regulators and not sure which one would fit my alternator. m998 92.
6. Info of of generating system - 60 amps, 25 volts, max/speed 10000 rpm, cage no. 52962, NSN 2920-00-909-2483, Spec Mil-G-46?/05 F (AT).
7. Prestolite Electronic Inc.

Soooo master HMMWV experts - Advice on regulator and any other input would be greatly appreciated. I cooked two Batteries Plus batteries already.

Sorry for the lengthy post, Thanks. J

 

[98G]

I'd upgrade to the 200 amp alternator and call it done. My understanding is that the 60 amp units frequently fail.

 

[Retiredwarhorses]

first off, you need good batteries...load tested.
check for output of the gen at the generator and at the batteries while running, the battery charging runs through the
PCB/EESS box. you can get new regulator for your specific Mfg gen on eBay...

 

[Mogman]

According to TM-9-2320-280-24P-1, (you should have already downloaded all of the TMs applicable to the HMMWV off of this site)
The part number you seek is AMA2004AS, NSN 2920011808666, I would also suggest replacing capacitor AMA1096, NSN 5910012181675 and the brushes, AMA1012S

Like 98G I am also a BIG fan of the 200A setup, I am told they very rarely ever fail (they don't even have brushes) and on those rare occasions it is almost always the regulator, being external would be very easy to carry a spare and can be changed in just a few minutes. and of course it balances the voltage between the batteries permitting 12V devices to be run with ease..

 

[92'M998]

According to TM-9-2320-280-24P-1, (you should have already downloaded all of the TMs applicable to the HMMWV off of this site)
The part number you seek is AMA2004AS, NSN 2920011808666, I would also suggest replacing capacitor AMA1096, NSN 5910012181675 and the brushes, AMA1012S

Like 98G I am also a BIG fan of the 200A setup, I am told they very rarely ever fail (they don't even have brushes) and on those rare occasions it is almost always the regulator, being external would be very easy to carry a spare and can be changed in just a few minutes. and of course it balances the voltage between the batteries permitting 12V devices to be run with ease..

Hi - I have downloaded the applicable tms and have a hard copy -10 manual. I feel like starting over with a 200 amp gen and new batteries is a good idea. What year did they switch from 60 amp to 200 amp? Thanks. J

 

[92'M998]

According to TM-9-2320-280-24P-1, (you should have already downloaded all of the TMs applicable to the HMMWV off of this site)
The part number you seek is AMA2004AS, NSN 2920011808666, I would also suggest replacing capacitor AMA1096, NSN 5910012181675 and the brushes, AMA1012S

Like 98G I am also a BIG fan of the 200A setup, I am told they very rarely ever fail (they don't even have brushes) and on those rare occasions it is almost always the regulator, being external would be very easy to carry a spare and can be changed in just a few minutes. and of course it balances the voltage between the batteries permitting 12V devices to be run with ease..

Hi - The Part number AMA2004AS is a different stock number (2920-00-116-8399 )that you gave me according to Eastern Surplus. The NSN you gave me is for part number SAW-11808666. They are similar but the SAW looks like the one that is on Gen. J.

 

[92'M998]

first off, you need good batteries...load tested.
check for output of the gen at the generator and at the batteries while running, the battery charging runs through the
PCB/EESS box. you can get new regulator for your specific Mfg gen on eBay...

Thanks. Since they are dead, I'm trying to charge. If not will get new batts and follow your advice. Thanks. J

 

[Mogman]

Hi - The Part number AMA2004AS is a different stock number (2920-00-116-8399 )that you gave me according to Eastern Surplus. The NSN you gave me is for part number SAW-11808666. They are similar but the SAW looks like the one that is on Gen. J.

If you google 2920011808666 you will come up with NUMEROUS references to AMA2004AS, I got those numbers out of the TM not from Eastern Surplus

 

[papakb]

I recently replaced the batteries in my M996A1 and after years of using Interstate 6TLs that only lasted about 28 months I decided to go with 24Fs. They are the same height and length as the 6TLs but a couple inches narrower so you can use your old battery hold down bracket with them. They have the same CCA ratings and come with a 3 year replacement that beats the snot out of the Interstates. I changed the routing of the cables to a much simpler path as you can see and you can use a quick disconnect jumper between them as a security measure if you want to. For whatever reason these 24F batteries come in 2 versions called North and South(????). One has flat top fill covers and the other has the old style raised fill caps. Look for the flat top batteries. Here's a picture of how this turned out:



Yes, they do fit into the original battery tray. I put some high density foam alongside the batteries but after several hundred miles of driving I don't see any evidence of the batteries moving. It does add some thermal insulation to the batteries too. They really simplify the battery compartment wiring .

The other nice thing about using 24F batteries is you can get them exchanged at Walmart and Costco and other readily available retailers that are open long hours instead of waiting until specialty shops open and going thru receipt hassles.

Last edited: Oct 24, 2018
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[92'M998]

If you google 2920011808666 you will come up with NUMEROUS references to AMA2004AS, I got those numbers out of the TM not from Eastern Surplus

Great. I also found it on Big Mikes's. Thanks. J

 

[92'M998]

I recently replaced the batteries in my M996A1 and after years of using Interstate 6TLs that only lasted about 28 months I decided to go with 24Fs. They are the same height and length as the 6TLs but a couple inches narrower so you can use your old battery hold down bracket with them. They have the same CCA ratings and come with a 3 year replacement that beats the snot out of the Interstates. I changed the routing of the cables to a much simpler path as you can see and you can use a quick disconnect jumper between them as a security measure if you want to. For whatever reason these 24F batteries come in 2 versions called North and South(????). One has flat top fill covers and the other has the old style raised fill caps. Look for the flat top batteries. Here's a picture of how this turned out:



Yes, they do fit into the original battery. I put some high density foam alongside the batteries but after several hundred miles of driving I don't see any evidence of the batteries moving. It does add some insulation to the batteries too.

The other nice thing about using 24F batteries is you can get them exchanged at Walmart and Costco and other readily available retailers that are open long hours instead of waiting until specialty shops open and going thru receipt hassles.

Last edited: Oct 24, 2018
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Hi- Thanks for the detailed pic. I am looking at all options. New regulator or just replace 60 amp Gen. all together. J.

 

[Milcommoguy]

I recently replaced the batteries in my M996A1 and after years of using Interstate 6TLs that only lasted about 28 months I decided to go with 24Fs. They are the same height and length as the 6TLs but a couple inches narrower so you can use your old battery hold down bracket with them. They have the same CCA ratings and come with a 3 year replacement that beats the snot out of the Interstates. I changed the routing of the cables to a much simpler path as you can see and you can use a quick disconnect jumper between them as a security measure if you want to. For whatever reason these 24F batteries come in 2 versions called North and South(????). One has flat top fill covers and the other has the old style raised fill caps. Look for the flat top batteries. Here's a picture of how this turned out:



Yes, they do fit into the original battery tray. I put some high density foam alongside the batteries but after several hundred miles of driving I don't see any evidence of the batteries moving. It does add some thermal insulation to the batteries too. They really simplify the battery compartment wiring .

The other nice thing about using 24F batteries is you can get them exchanged at Walmart and Costco and other readily available retailers that are open long hours instead of waiting until specialty shops open and going thru receipt hassles.

Last edited: Oct 24, 2018
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This Is a great conversion and easy on the pocket book and all the reasons posted. I have basically the same setup for the last 5 years. 60 amp alternator. I note and papakb has the covered battery terminals "booted" ... GREAT !

Whatever the reason one goes this route >>> MAKE SURE that the forward positive terminal is protected from moving forward and contacting the battery box. I placed a 1/16 inch thick sheet (4X7) of hard fiberglass and a couple of pop rivets to hold it in place. Now for sure it going to be very difficult to ground out the 24 volt terminal.

And don't forget to wear your booties, CAMO

 

[Ajax MD]

Pardon the hijack but I have a question regarding the 200 amp units-

When I start our truck after it has sat overnight or longer, after the Smart Start box does its little dance, the volt meter settles squarely in the green range.
After driving for an hour or longer, the needle drifts towards the yellow range and settles pretty close to the line. Still in the green range, but not by much.

Everything seems to work fine, headlights are bright, wipers are snappy, turn signals are fine. Is something happening to the regulator or the generator once it warms up?

 

[mechanicjim]

Pardon the hijack but I have a question regarding the 200 amp units-

When I start our truck after it has sat overnight or longer, after the Smart Start box does its little dance, the volt meter settles squarely in the green range.
After driving for an hour or longer, the needle drifts towards the yellow range and settles pretty close to the line. Still in the green range, but not by much.

Everything seems to work fine, headlights are bright, wipers are snappy, turn signals are fine. Is something happening to the regulator or the generator once it warms up?

For testing use a Multimeter when this happens and see what the system voltage is. once you are running there is less load as the battereies should have charged back up and the alternator could lower the system voltage a bit since its seeing less load. also there can be voltage lost due to a little bit of corrosion that only happens when the system/cables get hot. a multimeter check will confirm if the Alt is handling things. also a Amp clamp meter on DC amps can help see how much actual load is on when the vehicle gets hot.

 

[Ajax MD]

Ok, I'll put a meter on it and see what happens.

 

[juanprado]

Check battery voltage and load test

 

[papakb]

The gauges themselves are notoriously flakey and shouldn't be relied on for any serious troubleshooting. Always use a good voltmeter for voltage measurements. You can read actual battery voltage on pins V and W on the STE/ICE connector from inside the truck.

 

[Ajax MD]

Check battery voltage and load test

The batteries are brand new. The starter always spins with alacrity, whether it's 15F degrees or 95F degrees.

 

[Milcommoguy]

Like it's suppose too, CAMO

 

[frank8003]

Trucks for WAR designed to try to start 50 times, if one lets it all cool off between starts. That is as per directions. One needs Her to start and run.