Need some info on M100

[sergentsmess]

I have an M100 trailer that needs a wiring harness, It's a Dunbar Kapple with a delivery date of 12/52, Any idea what type of harness would be correct for this unit? Late or early? Facing the front of the trailer, there's no plug on the left side, only four small holes, the right side there are the same holes, with a small hole about 1/2 to 3/4 inch in diameter.

Thanks,
Chet
cking98@msn.com


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[wesk]

Hello Chet,

I haven't been able to nail down the date of the switch from two piece harness to one piece. It occurred the same time as the front harness storage box was dropped. Then at some later point the large round cutout for the plug receptacle in the right front frame corner was no longer cut out. The ORD 9 and -14P offer no serial cutoffs. And to make matters worse eventually the military only stocked the one piece harness which meant many were converted to one piece harnesses by the motor pools. Also the Army was known to remove the boxes because when turning very tight in reverse they often would contact the tow vehicle's tub. And also the mounting brackets for the boxes remained on the trailer tubs through the end of production. At this point it is simply a guess, if you have an early 50-51 trailer with the box still on it and the plug receptacle hole open then it could be assumed it came with the two piece harness.

[sergentsmess]

Thanks Wes, just what I needed to know.
Thanks for all you do on this forum.
Chet King

[wesk]

Chet,
I revised my replay and added after the box was installed that " and the plug receptacle hole was still open" .

Did I send you photos of my M38 with your tub I rebuilt on it?

As purchased from you a few years ago:





After painting 2 years ago:

[sergentsmess]

Hi Wes,
Wow, sure looks better than when it left here, you've done a great job with the restoration,
Wes, would know if there is a supplier for the Douglas connectors, I also need a replacement lunette casting for an m100 and looking for a wiring harness with the Douglas connectors, Thanks for your help and, again, that Jeep looks great.
Chet

[DanS]

Midwest Military should have the parts you are looking for.

[wesk]

Chet,
Keep your eye on ebay. That early harness comes up a couple of times a year. The difficult part to find is the receptacle that bolts in the large hole in the right front corner of the frame. It's pinned differently then the jeep trailer receptacles. The short front cord with the two large plugs comes up often as well. It is the same as the one used on the early 3/4T M101.

Do you only need the lunette ring casting or do you need the "V" casting and landing leg castings as well?


Here you can see the different plug ends. Female pin sockets on the left and male pins on the right. The male pins fit the jeep's receptacle.


This is the early layout.


This is the early trailer female receptacle with male pins.

Here's all the numerical data for this receptacle:

National Stock Number:
5935-00-752-5173

Federal Supply Class:
5935

National Item Identification Number:
007525173

Description:
CONNECTOR,RECEPTACLE,ELECTRICAL


Manufacturer Information:
12101-10 91340 MET-PRO CORPORATION

20859A 63810 WARNER ELECTRIC BRAKE AND CLUTCH CO HQ

3541 36024 LIBBY POWER SYSTEMS LLC

60-036028-51P (Original Bendix-Scintilla #) 77820 AMPHENOL CORPORATION DBA AMPHENOL AEROSPACE INDUSTRIAL DIV AMPHENOL AEROSPACE

60-036030-51P (Original Bendix-Scintilla #) 77820 AMPHENOL CORPORATION DBA AMPHENOL AEROSPACE INDUSTRIAL DIV AMPHENOL AEROSPACE

7525173 (Original Ord. Part #) 91971 NELSON MANUFACTURING CO INC

8376208 19207 U S ARMY TANK AUTOMOTIVE COMMAND AMSTA-IM-MM

8376208 53335 UNIVERSAL LOGISTICS CORP CLARK DIV

BG26996 18990 EAGLE CRUSHER CO INC

D7649-3 94833 KECO INDUSTRIES INC.

(DKI) 73-1615 (Original Dunbar-Kapple #) 98769 SENIOR OPERATIONS LLC DBA SENIOR AEROSPACE SSP DIV SENIOR AEROSPACE SSP

MS75021-1 96906 MILITARY STANDARDS PROMULGATED BY MILITARY DEPARTMENTS UNDER AUTHORITY OF DEFENSE STANDARDIZATION MANUAL 4120 3-M

MS75021-1P 96906 MILITARY STANDARDS PROMULGATED BY MILITARY DEPARTMENTS UNDER AUTHORITY OF DEFENSE STANDARDIZATION MANUAL 4120 3-M

[Rick_L]

Hello Chet,

I haven't been able to nail down the date of the switch from two piece harness to one piece. It occurred the same time as the front harness storage box was dropped. Then at some later point the large round cutout for the plug receptacle in the right front frame corner was no longer cut out. The ORD 9 and -14P offer no serial cutoffs. And to make matters worse eventually the military only stocked the one piece harness which meant many were converted to one piece harnesses by the motor pools. Also the Army was known to remove the boxes because when turning very tight in reverse they often would contact the tow vehicle's tub. And also the mounting brackets for the boxes remained on the trailer tubs through the end of production. At this point it is simply a guess, if you have an early 50-51 trailer with the box still on it and the plug receptacle hole open then it could be assumed it came with the two piece harness.

My Dunbar Kapple with a date of 5/51 had the remains of a two piece harness on it.

[wesk]

Rick, what is the serial number of your trailer? Do you have some photos?

[Rick_L]

01171768.

[sergentsmess]

Hi Wes, the part I need is the V shaped casting that the lunette ring and shaft fit into with only one hole. I believe the landing leg swivel also has 3 hole for a full up, full down and an intermediate position. Another question , I found a cable that is for the M151 mutt with Douglas connectors, will it also fit the M38? The seller says it's for the M416, and the M100.
Chet

[wesk]

The V shaped casting is difficult to find and often expensive. The swivel casting for the landing leg with 3 holes is for WWII trailers. The M100 and M416 use a two hole swivel casting. I have at least one V casting but it has the swivel casting mounting area chopped off. I'll do some nosing around.


MBT/T3 WWII vs M100 lunette.


MBT/T3 WWII vs M100 swivel casting.


M100 V casting

The cable you are being told of is for the late trailer harness where the intervehicle cable is connected to the trailer harness with Douglas connectors inside the drawbar "C" channel on the right. The M416 cable would most likely have the rubber Packard connectors.


This is the late M100 intervehicle harness with Douglas connectors.


The top wiring diagram shows the junction for the intervehicle cable inside the right drawbar "C" channel with a steel cover over it. The middle wiring diagram shows the early M100 harness with the intervehicle cable with a plug on each end.


Here's the late set-up again showing the junction area in the drawbar and having no receptacle in the frame corner hole.


Here's the early M100 set-up.

While you are building or buying a harness this is a good time to choose two rear service brake lamps (red) that can also be used with turn signals.


This is how to modify the wiring.If you do use turnsignals then you will need to run the right #22 separate and pin it at the corner receptacle to match the right turn signal wire in your jeep.

[sergentsmess]

Hi Wes, thanks for the pictures, my lunette looks like the one from WWII and has the smaller diameter shaft, the wedge casting is the one pictured that is missing the lower part. I'll stay with the one I have that's for the M416. As for the harness, I found one on E-bay that is identical to the one in the picture, its NOS and has the douglas connectors. Wes, I will get some pics of the trailer later today and post them

[sergentsmess]

[sergentsmess]