Xk150 wireing harness

Hi All…anyone had a 150 harness lately…mine is a 1960fhc …recieved mine a while ago and just started to lable it up…no wireing at all for handbrake, brake fluid reservoir and brake warning lamp…strange that i cant find a wireing diagram with them on (inc Viart, & Coventry Auto wireing book or Jag service manual)…havent yet asked the supplier to explain…Steve

I have rewired my very late XK150 3.8.
It was the first one with a brake fluid reservoir /hand brake lamp.
Early versions did not have them.
You can find a wire schematic in the XK service manual.

Hi Peter…i cant see the handbrake, reservoir cct on the diagram above…and cant see one with this cct in the Jag service manual…Steve

Correct, this is a separate option, see added picture from parts manual.

Hi Peter…thanks for the reply…yes im aware it was only on late cars…my question is re the wireing being missing from the loom even though i ordered a loom for a later car…and that i cant find a diagram for a later 150 with the brake warning cct on it…Steve

The old XK’s Unlimited had great wiring booklets by model. I got the ones for my E Type and my XK150. I would check with Moss and see if they still have them in stock. Each individual harness is addressed seperately so it is easy to trace your circuits by function.


If it’s that late, it’s probably very similar to the MKIIs.
If so, the dash brake/fluid light has two wires:

a white wire to the ign switch and A3 terminal on the fuse box
a red/green wire to the handbrake switch and to the fluid bottle.

The other wire on both the fluid bottle and handbrake goes to ground.

Hi…thanks for the reply…i can easily work out the Cct and colours as i traced out the old loom…just supprised its not on a diagram that i can find…and not in the new loom that was for a late car with the larger light unit and seperate amber flashers…Steve