VFR Rear LED light cluster showing broken wires

Repairing motorcycle rear LED light box

It’s MoT time of year and when I came to check over my bike I made the unfortunate discovery that the secondary brake cylinder had sprung a leak, and also the rear lights had stopped working completely.

Repairing the secondary brake cylinder was simple enough (using a repair kit from David Silver Spares), but I discovered that it is no longer possible to buy a new LED rear light cluster for my bike (Honda VFR 800 Fi-W – the first model of the pre-VTEC 800s). While I do have some spare standard light clusters, I like the LEDs and they match the front indicators, so I wanted to stick with the same style.

Fortunately, being lights, it was quite easy to see through to the LEDs and circuit behind, and it was fairly easy to spot the issue – the two signal (power) leads to the stop/tail cluster had become disconnected.

The fix should be simple – the difficulty being in getting into the unit. On first glance it looks really simple (clear cover with plastic back that essentially just clips in). Of course, while the design is quite simple, lights need to be waterproof, so there was a seal all the way round.

Releasing the clips (I used various plastic tools commonly used for removing phone cases for this) and use of various screwdrivers to break the seal and pull the cover off took around two hours (and involved me stabbing my hand with a screwdriver – the seal fights back!). I was able to remove without adding any further scratches or breaking anything, though.

Once inside, the repair was easy – just solder the wires back where they should be (as can be seen in the picture, two wires were hanging loose). I had to test which wire was which (one was stop the other tail, so it’s important not to get these the wrong way round) – easily done by connecting up to the bike and testing each one. The correct connections were:

Black wire -> G solder point
Yellow wire -> B solder point
Red wire -> S solder point

Once soldered, I covered with some gorilla tape to add a little more strength. After checking I could put the unit back together properly, I used silicone adhesive to replace the seal all round and then joined the parts back together. Hopefully they’ll last a few more years.

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