Can anyone confirm if I require the Caterham High Level Brake Light Loom for 2018 car, or does it have a different connection?
That vintage must already have the loom. Should find cable in boot or under boot floor
Look for a spare connector block, probably cabled tied with other parts of the loom to the frame between side of fuel tank and side skin, towards the RHS bottom rear of the chassis.
Having fitted a 3rd light for 2 cars so far fortunately I haven't had to take the boot floor out!
If you can find an existing feed please tell us the colour of the wires so that we can check that it is for brake lights.
According to the 2015 Assembly Guide, you need to insert the sub-loom connector here:
This shows the kit contents:
Of course, your later car may already have the sub-loom fitted (as Benton says in #3).
Just for further clarification of my earlier post, it's the clear plastic connection block is the one you are looking for/need to hook up to if it's present, which it certainly was with both my 2018 cars.
If in doubt check with a multimeter and an assistant to press the brake pedal to confirm.
#6 Wot he said.
My 2016 car had two Lucar spade terminals (female IIRC) shrouded in opaque white plastic covers between skin and tank on O/S.
#6: Thanks for that.
This highlights another shortcoming in the current set of Assembly Guides -- namely, no up-to-date wiring diagrams. The latest diagram I have (from 2015) makes no mention of a high-level brake light (as you would expect as the connection was via a sub-loom hooked into the existing RH rear light connector).
The Just Add Lightness "how to' Video may be useful reference if you've not found it... Its talking about their brake light, but talks about cable runs, and the location of the sub loom.
To your original question, You should have the Subloom already fitted as others have suggested on the right hand side between the tank and the skin tied/taped somewhere. My 2016 car did...
Following the points about identification above, and for those not familiar with Caterham wiring:
1 Some Sevens have the feed and connector already installed. (Colours to be added)
2 Some Sevens have the feed and connector for an accessory power source in the boot! (Colours to be added.)
3 You can identify what you've got from the colour of the wires, by putting a multimeter on the connector while the putative circuit is live (ignition ON, brake switch CLOSED), or by connecting a lamp. LEDs only work when connected one way round.
4 We have the factory wiring diagrams for nearly all Sevens. And here are the common wiring colours for British cars, which Caterham usually follow.
My 2013 car has both 3rd brake light and accessory (cigar lighter) connector cabling in its boot.
The latter but not the former appear in the contemporaneous wiring diagram.