Electrical Connector Block


Active Member
I've been doing a bit of work on fixing up my wifes horse trailer and everything was going fine until it came to the electrics.
Below is a picture of the connector blocks used to wire up the lights - the problem is that I cant get them open to get to the wires. I've tried popping them open along the blue block but they are either stuck fast or thats not how they open.
Anyone have any experience of theses or know somewhere that sells these or similar so I can just cut the old ones off.

(sorry about the poor quality picture but you get the idea.)



Distinguished Member
0 out of 10 for the poor photo :) but looking like it they are the self piercing type connectors.
The centre part will most likely have two barbs, a bit like the old scotch lock.
Then you lay the two core cable into the centre part, then blue bits push the wire onto the barbs and it makes the connection. The blue bits latch onto the side of the centre bit.
if you follow that.
So you should be able to remove the blue bits by prizing them off, but then you need to pull off the wire.
Honestly the best course of action is likely to be cut this connector out, do a new join with water proof cut and butt heat shrink connectors. Or a junction box.

I use these connectors on commercial vehicles and the idea is they are one hit connectors.


Distinguished Member
One more thing to add, its not likely to be the blue outer that's the problem. The barbs that have pierced the two core cable is likely to be the culprit, so even with new parts, it may not solve the problem.
Personally I would do it properly, rip out all the current electrics and do it again with proper normal connections.

EDIT: Another thing to add, the reason these connectors are used is that the main 2 core cable is treated a bit like a ring main. You run a loop of this wire into all corners of the body. Then you get a lamp with a short length of cable, run it to the nearest bit of 'ring main' and crimp it on. If a lamp fails, you can cut off the tail, seal the cut end crimp a new lamp next to the original crimp location. In theory, brilliant. In practice... meh.
Also the ring main wire is often square section (to sit in the blocks straight) and this can give issues when reworking, ie passing through grommets, heat shrinking. So rip it all out and start again. Honestly it is the best thing to do.
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Active Member
@balidey that's the exact ones and if nothing else at least I can see how they work! I think starting again is the right call, there is enough spare cable around to sort it properly.

I can always rely on someone on here to come up with the right answer!

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