Custom Hitch and Trailer Plug Converter Box

[Cole667]

I built this custom adapter box and hitch for my m923a2.

The converter box converts the 12pin 24V plug on the truck to a 7pole, 7blade, and 4 flat 12V trailer plugs. It also has a 12V outlet. Inside the box is an electric brake controller. The toggle switch is used to send power to the reverse pins on the plugs due to the fact that the truck does not have a reverse output. The box utilizes four 24v to 12V voltage converters. A "2 wire to 3 wire trailer adapter box" is used to give the trigger for the brake controller. All 7 funtions of the trailer plugs are functional. Future upgrades to the converter box would be the ability to have the brake controller and reverse switch in the cab via a long cable that would plug into the box. I wanted to keep this box removable and portable so that it can be used on multiple trucks and didn't want to modify my truck. If anyone is interested in one of the converter boxes let me know.

The hitch is a standard heavy duty Curt hitch. I wanted to keep the hitch tucked up out of the way so that It would not hang me up offroad or interfere with the use of the stock pintle hitch. In order to tow my camper I needed an 18" extension. I welded a hitch tube to either side of the hitch and fabricated an extension that slides and pins into all 3 hitch tubes. I also added turnbuckles that add extra support. I feel that the turnbuckles are not necessary, due to the fact that the curt hitch is rated for 2,550lbs of tongue weight and the 900lbs of tongue weight my camper has at 18" of leverage is still within the rating, but I would rather it be overkill. I finished it off with a 12.5" drop Gen-y hitch.

The rig is 61ft long and 30,000lbs.

 

[Hamrick907]

Hitch looks good, thanks for the idea.

 

[Jbulach]

Cole667,
If your interested, I believe there is a thread on where to install a pressure switch in the transmission. This allows you to have backup lights switched automatically when shifted into reverse.
Sorry I can't find the exact thread and I'm not a very good position to search right now...


M925A2 with dump hoist

 

[603hellmutt]

Do you happen to have a part number for the hitch? Been looking to put one on my 923 that trailer plug box is innovative

 

[aleigh]

Pretty cool!

 

[Spyderman]

I am very interested in your box you built. How much to buy one from you?

 

[603hellmutt]

I also would love to buy one of those boxes. Make my life a lot simpler.

 

[Hamrick907]

I'd buy one

 

[f800]

I am also interested in purchasing one

 

[cq141]

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I built this custom adapter box and hitch for my m923a2.

The converter box converts the 12pin 24V plug on the truck to a 7pole, 7blade, and 4 flat 12V trailer plugs. It also has a 12V outlet. Inside the box is an electric brake controller. The toggle switch is used to send power to the reverse pins on the plugs due to the fact that the truck does not have a reverse output. The box utilizes four 24v to 12V voltage converters. A "2 wire to 3 wire trailer adapter box" is used to give the trigger for the brake controller. All 7 funtions of the trailer plugs are functional. Future upgrades to the converter box would be the ability to have the brake controller and reverse switch in the cab via a long cable that would plug into the box. I wanted to keep this box removable and portable so that it can be used on multiple trucks and didn't want to modify my truck. If anyone is interested in one of the converter boxes let me know.

The hitch is a standard heavy duty Curt hitch. I wanted to keep the hitch tucked up out of the way so that It would not hang me up offroad or interfere with the use of the stock pintle hitch. In order to tow my camper I needed an 18" extension. I welded a hitch tube to either side of the hitch and fabricated an extension that slides and pins into all 3 hitch tubes. I also added turnbuckles that add extra support. I feel that the turnbuckles are not necessary, due to the fact that the curt hitch is rated for 2,550lbs of tongue weight and the 900lbs of tongue weight my camper has at 18" of leverage is still within the rating, but I would rather it be overkill. I finished it off with a 12.5" drop Gen-y hitch.

The rig is 61ft long and 30,000lbs.

im trying to do something similar im trying to convert the plug on my Humvee and hitch to hook up and plug in to a civi dump trailer don't suppose you have any tips or suggestions for me

 

[cq141]

if your willing to sell me one Instead that would be great

 

[603hellmutt]

If he is willing to share his schematic I'm sure I can get something set up.

 

[my blood flows OD]

I wouldn't want to ship one of those boxes. Can you imagine that going thru a scanner somwhere. Haha that thing definitely looks suspect.
really nice work though. I love the use of the ammo can!

 

[Steelreaper80]

Have any for sale?

 

[LanceRobson]

Cole667,
If your interested, I believe there is a thread on where to install a pressure switch in the transmission. This allows you to have backup lights switched automatically when shifted into reverse."

There's an 1/8" NPT plug in the passenger side of the tranny by the ID plate. Screw the switch in and wire it up. The port is only pressurized in reverse. See:

http://www.steelsoldiers.com/showthread.php?112351-M939-5-Ton-reverse-light-switch


Lance

 

[big block 88]

Man that looks great good work sir. My only question is (and by the pics you seem more than adequate) always make sure your welding ability is up to snuff. A trailer loads the welds in all directions and can fatigue it quick fast and in a hurry without proper penetration. You welds look to be fine though this is more of a heads up for others to be realistic about their abilities.

Multi pass welds are never a bad thing if in doubt.