Yes both horns are original to the car, car was built in Aug of 1955 and is a 1956 model year.
So I shot a video of just the low horn and then I re-attached the high horn and shot another video of both of them together. I have to tell you that it sounds plenty loud to me and I can hear the oscillation between the tones of both horns, hopefully that comes across in the videos. Let me know what you think.
Ack it won’t let me upload so let me put the videos somewhere and link to them…
Hi Ken, thanks for the videos. On my XK140 only the low horn works. Your videos however convinced me to not bother fixing the high tone but rather replacing both horns with windtone horns. I want my horns to be really loud. They should alert another car 30 meters from me driving at a 80mph on a highway. The XKs are small cars and might easily be overseen. Without a lot of crumple zone I will feel safer with very loud horns.
Question: Almost all windtone horns I have seen have just one wire. Earth is provided through the mounting. Is it better to have two wires on a XK (or, how good is earth from frame to chassis)?
There are some (look for zinc diecast) knockoffs on ebay that are supposed to be really loud. They don’t say Lucas, it’s just the tried and tested design. Would be a nice extra loud horn. Anyone who has tried them?
Is there a reason they would be?
The core is just iron, not magnetic like a speaker, and the coil attracts it and lets go for each cycle.
The condenser shouldn’t be polarity sensitive, that would leave you with point wear.
If you connect them as they were they will work and be just as they were connected before; if you swap the wires they will last longer as the other side of the points will now wear more. I don’t see how you can lose.
Regarding the condenser: the earlier Lucas HF horns (ALTETTE HF.1234 and 1235) didn’t even have a condenser, it was merely added across the points to “prevent excessive sparking” as Lucas describes the addition of condensers for the new range of High Frequency horns HF 1746, HF 1747 and the better known HF1748.
The Lucas “Windtone” horn type never had a condenser (as far as I know).