Notes on originality.
The cables in harnesses are of 3 types depending on the year of manufacture. Prior to 1935 cable production was rubber insulated, cotton covered and laquered in Black. Secondary colour was identified by coloured rubber rings at ends of the cables. In 1935 Lucas commenced production of coloured cables with the secondary tracer colour banded in the cotton cover. This was a herringbone pattern and had 33 different colours. We can still obtain this cable for pre war harnesses and use it in our manufacturing process for these early cars. Post World War II with the advent of heaters and more complex electrical circuits Lucas introduced a new 66 colour version of their colour code. This was still cotton braided cable with a trace colour through the base colour therefore dispensing with the need of the earlier herringbone pattern. Where appropriate we still use this style of cable. From 1945 with the development of PVC in World War II, a small amount of PVC began to be used. At first in the instrument panel harness, then the black earth wires. Progressively through the 1950's more PVC was introduced until about 1960, when M.G.'s became 100% PVC cabled. Jaguar about 90% PVC with 10% cotton covered.
Our research has proven that the outer covering on the wiring harnesses on M.G.s up to 1940 were braided in Khaki brown. Post 1945 in black. Most other Lucas harnesses post 1935 were braided in black this includes SS Jaguar and Jaguar. A secondary reference tracer was introduced as a code in the outer braiding. This outer tracer colour code changing if the harness or individual harness section changed in detail with the upgrade of a model, or with a change in specification mid production run.
Some later harnesses (1970s) and sections of harnesses were taped with a black non adhesive loom tape. We also use this where applicable on our harnesses.
We have a 'museum' of original harnesses that we can refer to for specific details to ensure that originality that we are so fastidious about.