Hazard warning light option

I have this original feature on three 1967 cars, sold new in the US.
On an E-type it is not working. What is the probable cause?
A hidden fuse, bad earth, wiring issue behind the cover boards under the steering column, or…?
Many thanks,

No extra fuses involved but probably the hazard flasher unit:


Easy to replace.


Great. Thank you. And very cheap😅
Where might that be hiding? Behind the folding instr panel I hope, but as itś quite crowded there, Jaguar probably hid it somewhere else, requiring a panel to be removed.
(Your tip on installing this feature on cars which lacked them, is very elegant!)

Look behind the small panel where the hazard warning lamp and switch are located.

But there is no relay on the back of the panel on my car. Must be hidden somewhere…:scream:

Where do the wires go from the hazard warning switch?