High level rear lights- Part 2- 9 Apr 2016.

Having finished the wiring on the bike for the lights on my top box, it was now time to work on the box itself. I offered up the light to the box to work out where to drill the hole for the wiring. I stuck on some masking tape, marked the spot and drilled the hole (4.5mm). I haven’t used a grommet and made sure the cable would be a snug but not tight fit.

The light unit has a self adhesive backing so I cleaned the area it was to go with methylated spirits and stuck it on. It is well and truly stuck even though the surface is not absolutely flat. I decided to put it on the lower section of the box so I didn’t have to mess about taking the wiring around the hinge.


A hole then had to be drilled to let the wire out again. I threaded the wiring through then marked where I was going to cut the cable to length.


Back on the bench I chopped off the excess cable and took a look at the individual wires. They are very thin with an overall diameter of 1mm. The yellow waterproofing plugs I have for the AMP connectors are for wires with an OD between 1.7 and 2.4mm. You can buy green ones covering 1.2 to 1.6mm but these still wouldn’t be right.

I used the off-cut of wire to experiment. My solution was to add a piece of heat-shrink sleeve to the wire to make it big enough to fit the plugs I’ve got. Then there’s the copper wire itself. I stripped the insulation so that I could fold back the cores to give me four times the thickness and crimped them using needle nose pliers rather than my ratchet crimpers. I wouldn’t usually recommend crimping folded conductors because you are more likely to be able to pull them out. Here I had no real choice as soldering them would most likely do more damage. My test item seemed to be tight but I decided to put a blob of “Wire Glue” into the crimp. The stuff was hanging about after I used some to repair the buttons on a TV remote control.



I gave it the morning to dry then tried pulling it apart. The wire broke but the connector didn’t pull off. Pleased with the result I used this method to fit the connectors to the five wires from the light. They were glued and left standing upright so that the glue stayed in the crimped section.


Once dry the rest of the AMP Superseal plug was assembled. It goes together in the same way as the socket. This time the red locking piece goes on the nose of the plug.


The box was fitted to the rack and the cables connected.



As you can see, I relocated the socket from underneath the rack to the indicator bracket.

Now it was time to test everything and something was wrong to start with. The left hand indicator flashed the tail light and the tail light put on the winker so these appeared to be transposed and there was no brake light at all. I checked the socket terminals on the bike with a test light and all worked as it should. I then used the bike’s battery to test the terminals in the plug and found all the lights on the box worked properly as well. I fitted everything back together and the fault repeated itself! I gave up in disgust and went and had my dinner.

I went out again later and dismantled the plug attached to the box and could see nothing wrong with it. I inserted the individual pins in the socket methodically testing each of the circuits.

-Earth pin and tail lamp – good.
-Earth pin and brake light – good.
-Earth pin and both these together – still all good.
-Earth pin and LH indicator – good.
-Earth pin and RH indicator – good.
-Earth pin and both indicators – both work.
-Earth pin, both indicators and tail lamp – all working.
-Earth pin, both indicators and brake lamp – yep, all good still.
-The whole lot – and it all flippin’ worked. What is going on?

So, I reassembled the plug and the fault had gone away! I wiggled wires, disconnected and rejoined the plug and socket a few times and it didn’t come back.

If you remember, I made a “dummy plug” to use when there’s no top box fitted. This had hardened off and fits like this.



I stuck the cable to the inside of the box using black “Duck” tape. Not my best work.



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