CUCV 6.2 K5 Trailer wiring?

I have a 1986 K5 Blazer CUCV. I am modifying the original pintle hitch with a combination pintle-ball hitch and want to be able to pull my boat trailer with the lights working properly. There is a military receptacle where a military trailer would plug in, located next to the pintle hitch. That receptacle is fed by two three-wire groups that have quick connect's (located up under the truck's rear bumper). My question has to do with the color coding of those 6 wires (two groups of 3 wires each). Does anyone know what color wire goes to the taillamps, brake lamps, and directional lamps? Also, the hi-lo beam selector is on the steering column, but there is also what looks like an old-fashioned dimmer footswitch located on the K5's floorboard to the left of the brake pedal. It's a momentary switch...........is that a control switch for trailer brakes? I'm relatively new to this military vehicle stuff and thought I'd ask for advice and help before I wired something up wrong and caused myself a major problem. Thanks in advance for any help you can offer me. By the way, one more question...... stenciled on the cab ceiling above each door of my K5 are the letters "NFOGHA". Curious what those letters stand for......if anyone can help, I'd appreciate it. Thanks again!
Warren

I was under the impression that the military trailer lights were 24V. Might want to put a voltmeter to it.

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I'm guessing your boat & trailer don't weigh that much, but I'd recommend a receiver hitch.
You can buy a 4 way T adapter for trailer wiring, use 84 as the year model.

Lots of options for you.

[h=1]M1009 Trailer Connector Wiring Diagram[/h]
[h=1]4 prong trailer wiring T connector[/h]
[h=1]Civy truck to MIL trailer wiring info[/h]
[h=1]M1009 trailer wiring harness to standard civilian trailer harness[/h]
[h=1]Trailer light plug options[/h]

glaser06 said:

I was under the impression that the military trailer lights were 24V. Might want to put a voltmeter to it.

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CUCV's have 12v to the trailer wiring circuits.

86m1028 said:

I'm guessing your boat & trailer don't weigh that much, but I'd recommend a receiver hitch.

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Very good advice, I think.

Much thanks to Porkysplace and the rest who replied to this thread...........very appreciative for the input.

pickinitup said:

Much thanks to Porkysplace and the rest who replied to this thread...........very appreciative for the input.

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When you use the site search function use M1009 instead of " K5 blazer ".

Chief_919 said:

CUCV's have 12v to the trailer wiring circuits.

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The CUCV trucks, 1008 and above I believe have 24V at the trailer plugs and the M1009s have 12 volt wiring. I would just go on epay and purchase a Military to civilian trailer adapter plug, they sell several types. This way is a simple plug & Play and saves a lot of unnecessary rewiring that that will limit you to what type of trailer your pulling and also will keep your truck more original.

All CUCV trailer wire supply is 12V. There are 3 good options. One is buy an adapter. Make sure it's from miltary vehicle to civy trailer, not vice versa. The hoppys plug in adapter sounds good too. Be certain it is for a 1984 blazer regardless of the year of your truck. Third is build a replacement using weatherpack connectors that are on the truck. A nice schematic of the wiring is in the appendix of TM 9-2320-289-20. Those are free in the TM section of Steel Soldiers.

Happy Motoring

Recovry4x4 said:

All CUCV trailer wire supply is 12V. There are 3 good options. One is buy an adapter. Make sure it's from miltary vehicle to civy trailer, not vice versa. The hoppys plug in adapter sounds good too. Be certain it is for a 1984 blazer regardless of the year of your truck. Third is build a replacement using weatherpack connectors that are on the truck. A nice schematic of the wiring is in the appendix of TM 9-2320-289-20. Those are free in the TM section of Steel Soldiers.

Happy Motoring

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I stand corrected about the M1008 trailer plug voltage, maybe it was the HMMWVs I was thinking of. And the photo I showed is for a military trailer to a civy truck not the other way around.

Reviving this thread. I am kinda confused here. Can someone please verify?

I have always been under the impression that the M1009 trailer wiring circuit is 24 volts. I am reading here that on M1009 trailer wiring is actually 12 volts? Is this correct for the NATO Connector as well?

I have a civilian trailer that's 12 volt. I want 12 volt 7 pin trailer jack. Then I can make an adapter from NATO Connector to 7 pin connector. This should work correct without having to reduce voltage to 12 or changing bulbs on trailer to 24.

Thank you,

John

Confirmed, the trailer wiring is 12V but the slave plug on the front is 24. The wires on the passenger side of the back seat should be 24V as well.

There's always the option of using a simple Volt meter (or even a test light) to confirm that things are still wired as intended, just in case.

The factory trailer plug on my M1008A1 is 24v.
Have looked underneath and it’s not hacked or been modified.
All original
Lights on both my M101A2’s work perfect when hooked up to it.

Tinstar said:

The factory trailer plug on my M1008A1 is 24v.
Have looked underneath and it’s not hacked or been modified.
All original
Lights on both my M101A2’s work perfect when hooked up to it.

Click to expand...

Not to argue but your truck is NOT factory wired 24 volt at the trailer plug. It will light 24 v trailers but not as bright as it is intended. I pulled 416 trailers with my M1009 for years with the 24 volt bulbs on the trailer. They work just not as bright as intended. That trailer plug is all 12 volt. If it were 24 volt it would require all the bulbs on the truck to be 24 volt. I have split the harnesses and they are all tapped into the same wires as the tail lamps. Have a great day. If you are pulling a 24 volt trailer with your CUCV. All is well. But if you want it to have brighter lights. Do a bulb change to 12 volt bulbs. Huge difference. Just don't hook it back up to a standard MV with a 24 volt trailer receptacle.

The only parts of the CUCVs that are 24v are part of the starting circuit and part of the glow plug circuit.

If you actually measured 24v at the trailer receptacle you have something wrong.

It's also very common to have 12v bulbs installed on m101a2 trailers from the military, seeing how they were built to be towed behind a CUCV with 12v trailer lights. I've also had m416s with 12v bulbs, some were stenciled with 12v on the tongue some were not. Since they were CARC green painted it's possible they were used behind m1009s.

Well I’m not infallible.
I have not checked with meter
Will today.

Assumption is evil.

Assumption is the Mother of all *uckups.

I always assumed and never physically checked the trailer plug voltage.
Military trailer plugs in, gotta be 24v right?!.........wrong!!!

Boy do I feel like an idiot.
Crow tastes terrible BTW.