NATO trailer plugs and sockets, inspection/disassembly

[Carzee]

Hi, I am removing and replacing the NATO plug on the trailer which may be 20 years old or so. I may also check the socket on the vehicle. Both items are working okay but I am fitting a new plug to redeploy the old plug as an adapter for the 7 pin system on the civvy trailer now that I have a Hayman Reese combo towball tongue and pintle fitted to the vehicle. (Hayman-Reese Towbar part number 01532, suit Pajero, older model).

I loosened the ring clamp on the rear body of the plug where the trailer loom cable is held in place. I pushed it forward thinking the rubber plug with the pins would move forward out of the front of the plug and allow some inspection of the soldered pins and wires..

...but there seems to be a corrosion problem or an adhesive sealant on the rubber that will not let it budge.

What is the best way to get it out? WD40? Anyone experienced this?

[aussiegregmac]

You've got the basics ok but it does need a little persuasion.
Both parts are similiar.   Ply with wd40 maybe but it goes best with
a little rubber grease or similiar for lubrication.

Use a small flat headed screwdriver to get behind the rubber to ensure it's
not glued and eventually you can (gently) lever if out.

The whole rubber plug and wiring comes out complete.
If you need to repair or replace the wiring push the pins out one at a time
with pointy pliers.  Easy Peasy.
Greg Mac.

[Carzee]

Thanks for that. Will give it another go tmrw before work. I have been out there 45 minutes prying with a flat blade but no result so far.

[Carzee]

Its out. I ended up using 4 teaspoons (the handles, not the scoop) instead of screwdrivers. It was no better, no progress. Then I got the pins out with pliars and the rubber bung was then more 'squishable' by the teaspoon handles and when I pushed the fat cable (the cable that goes under the trailer) the bung moved a bit in the steel cylinder and then some more until it was all the way through the NATO plug 'tunnel' -the bung, the back of the pins, and the wires were then free to check over.

The solders were all good but the wires had varying amounts of contamination and breakdown. Some have bright copper but some will need to be stripped back to find bright copper. Most of the wires are white. The earth (Pin D) was black. One of the wires was yellow with a green stripe.

To make it simple when fitting the new NATO plug and pins I have labelled each wire with its pin letter (ie A,B,C,D,E,H, I, L, M, N)(F and K were blank/empty pins and there are no G and J pins). The labels are just heatshrink. Before I heated the heatshrink I used a permanent marker to write the letter on it.

[Carzee]

Turned out okay. Finished it today with thunderstorms all around.

Here's my diagram - http://www.remlr.com/wiki/index.php?title=File:RC-12pin-adapter-diagram.jpg

Here's a photo - http://www.remlr.com/wiki/index.php?title=File:RC-12pin-adapter.jpg

[Diana Alan]

Just thought I'd add my NATO 12 pin the civilian 7 and 12 pin conversion tables.

In relation to the civilian modified table, in the Australian standard there is no pin for the reversing lamp nor electric (Service) Brakes, for those of us who have trailers with electric brakes or reversing lamps and who don't want to add a civilian socket this design allows a minor modification to serve these functions.

In the No 5 trailer, Series IIa and III pin J is not used, so the presence of the electric brakes on that pin should not cause any problems. When coupling a trailer with electric brakes to a tow vehicle without the wiring modification (particularly Perenties where Pin J is active) it is important to disable Pin J on the vehicle end because the activation of a stop lamp signal will put the electric brakes on full, where the current draw may blow fuses. ( each braked axle will potentially draw 3.0 Amps)

Similarly Pin J which is the third convoy lamp signal which becomes the reversing lamp. This should not cause significant problems because it is unlikely that convoy lighting would be used on a public road when the trailer reversing lamps would be illegal.

N.B. In all cases, in spite of the standard schematic, you should check and rectify any incompatibilities before coupling trailer to vehicle.

(the third diagramme is a pair of European/Belgium standards, it should be noted the significant differences in the UK/Au specs (so much for NATO standardisation and interoperability))