M101A2 24 Volt to 12 Volt Conversion

[Texas Manny]

Hi Y'all,

My name is Manny and I'm from Texas. I just joined Steel Soldiers as I was referred by the gentleman I just purchased a beautiful M101A2 trailer from. The world of owning military equipment is new to me, but I am familiar with it as I am a veteran of the armed forces.

I did an advance search in the trailer section on converting 24 volts to 12 volts and found a few threads but they still leave me confused. Here is what I want to do:

I want to maintain using the stock tail/brake lights on the trailer. I have the conversion bulb numbers to go from 24 to 12 volts. My issue is going to be with the connector at the head of the trailer. I want to replace that with a 12 volt unit. I do wish to be able to keep the 24 volt connector if possible should I decide to ever sell the trailer, which I doubt. May I ask you for some help here. I'm towing the trailer behind my 83 Chevy K10 which is the equivalent to the CUCV series, just 12 volt.

Thank you!

Regards,


Manny

 

[Recovry4x4]

You have a few options here. That trailer plug assy is attached at a connector under a shield on the left front of the trailer. The military packard connectors with interchange with bullet connectors so its as easy as unplugging one and making up another. If you sell the trailer you can swap it back easily. You could add tee connectors to the original stuff and add the other plug too but you would have to source them from a surplus supplier. The last option is to put a military plug on the back of your K10. I added the mil connector on my Suburban and it works great.
Oh, welcome to the site.

 

[JB]

I actualy did not change the bulbs in any of my trailers. The 24 volts are not that much less bright (I don't think), but it did switch to the composite lights for greater visibility. Also, i wired a civi wiring hookup into the existing junction box so i could pull with my civi truck and kept the military plug as well for the military vehicles.

 

[Blood_of_Tyrants]

A third route you might want to consider is to get a connector off a junked CUCV and connect it to the military connector on the trailer and then wire that directly to a civilian connector. No mods at all to the existing wiring harness.

 

[Texas Manny]

Hey Guys,

Thanks! Those are all great idea's. I'm liking the CUCV connector wired into my truck idea. Does anyone have any wiring schematics for that?

Thanks!

Manny

 

[Texas Manny]

Quick question: What is the proper terminology for that CUCV Connector. I found an NSN for:

RECEPTACLE, SLAVE NATO 01-097-9974 REPLACEMENT PIECE
Just don't know if that is it. Where would y'all recommend getting the CUCV connector. I prefer NOS if possible.

Thanks again!

Manny

 

[PeterD]

Quick question: What is the proper terminology for that CUCV Connector. I found an NSN for:

RECEPTACLE, SLAVE NATO 01-097-9974 REPLACEMENT PIECE
Just don't know if that is it. Where would y'all recommend getting the CUCV connector. I prefer NOS if possible.

Thanks again!

Manny

That is the 'jumper' cable connector. Allows connecting two vehicles together to quickly start one with a dead set of batteries.

What I'm doing with my M200 trailer is just getting a 7 ft 'pigtail' with the seven pin round RV type connector on it, and using either bullet or getting some Packard connectors. I'll keep the old harness/connector for the day it is perhaps needed. In my case, I've three potential tow rigs (two Hummers, and a Dodge 2500) so using the CUCV connector is not a good option.

 

[Recovry4x4]

If you find the CUCV trailer plug, the wire colors will be correct for your application. That means yellow will be left turn, right will be green and the running lights will be brown.

 

[john.dunlap]

I actualy did not change the bulbs in any of my trailers. The 24 volts are not that much less bright (I don't think), but it did switch to the composite lights for greater visibility. Also, i wired a civi wiring hookup into the existing junction box so i could pull with my civi truck and kept the military plug as well for the military vehicles.

Got a better picture of which plugs you went to with the four wire flat plug? I want to do the same thing but will be removing the military plug. Looks like you did a real good job with the wiring.

 

[PeterD]

I would strongly recommend changing the bulbs to 12V bulbs (or dual voltage LEDs if you can!) One thing you don't want to have happen is for someone to rear-end your rig and then say "I couldn't see the lights" and have the investigators find you were running 24 volt bulbs on 12 volts.

 

[sigo]

Peter,
Got a NAPA part number or a another source for the dual voltage LEDs?

 

[PeterD]

Napa? No, sorry. I get most of my LEDs from SuperBrightLeds, IIRC superbrightleds.com. Their products are good. Most of teh military replacement LED units are dual voltage. Since most trailers use standard assemblies just like the back of trucks, that makes things easier: eBay is your friend there, and there may be a NAPA number for complete lights, but I don't know what it is. (IIRC, Peterson makes them.)

 

[KsM715]

Got a better picture of which plugs you went to with the four wire flat plug? I want to do the same thing but will be removing the military plug. Looks like you did a real good job with the wiring.

On those connections under that cover the wires should have little metal tags.
On the four flat trailer plug I dont remember wich is wich as far as left and right, green and yellow, That should be in the package with the connector when you buy it. But take the yellow/brown and the green brown and tie it to wire 21, thats the taillights. Wichever color wire goes to the left (driver) side will go to 22/461 and the other wire for the right (passenger) side will go to 22/460. Make sure you run the white ground wire to the frame of the trailer.

 

[john.dunlap]

Thanks for the wiring diagram, just no metal tags on my wires. Probably long gone. I think I have enough to make it happen.


Results orientated

 

[STSR]

Here is another option, I just did this on my trailer to make the rally in Ga this week. I have to keep the 24v set up because I use my 101a2 with my duece and hmmwv. I went to autozone and bought a trialer light kit (LED) and it was on sale for $50.00 I was fortunate to have some angled brackets in CARC tan already, so I drilled some extra holes in them and mounted the new lights to them. I then remove a couple of bolts from the trailer (rear under lip) and bolted them right in. Best part was you can still see the factory lights. It looks good and only took about 20 minutes. I routed the wires under the frame and zip tied them in several places. The kit came with all I needed, sans the wire ties and brackets. Hooked it up to my dodge 3500 and good to go.

Just another option.

 

[KsM715]

$50 I just put a set on the trailer Im selling for less than $20 from the local farm supply store.

 

[kstrekker]

I just switched out the 24V bulbs on my M101A2 and I'm glad I did. The 12V bulbs are much brighter. I plan on keeping my trailer OD Green with the woodland camo cover, so the brighter bulbs help me be seen on the highway.

 

[STSR]

$50 I just put a set on the trailer Im selling for less than $20 from the local farm supply store.

The ones I bought were LED trailer lights in kit form. I've never seen that kind of set up for $20.00, at least not in LED. Not to be a smart egg, but if you can get LED trailer light kits for a price that you can sell them $20.00 I'm all over it.

Todd.

 

[KsM715]

Sorry, I missed the LED part. They had the LED kit but I went with the el-cheapo $18.99 special. If it were my personal trailer and I needed new lights I would probably spring for the LED's too

 

[STSR]

Sorry, I missed the LED part. They had the LED kit but I went with the el-cheapo $18.99 special. If it were my personal trailer and I needed new lights I would probably spring for the LED's too

Your eyes are as bad as mine