MKIV Semaphore Orange Lenses

Hello Friends,

Does anyone know of a source for the orange / amber lenses for the semaphores?

Mine have both been broken and re-glued (poorly) at some stage.




try vintage car parts
Semaphore (orange) plastic blade to fit Lucas SF80 trafficator, (equivalent part 532026). overall length 180mm.

SF54 or 55, £195 or £245


Worcester Classic does an exchange service but I expect they would do it through Classic Electrical Spares. Try contacting jimmytheparrot here in Aus via his e-bay postings too. He sells some parts plus complete refurbished units. He also has a detailed explanation of how to wire them up to suit a variety of operations - eg ‘highway mode’. This has a manual override, as the arms don’t always return at highway speeds due to wind load. This mode is also useful when stopping at the kerb so that you can cancel the arm early with the other flashers on so that the rear passengers don’t strike the raised arm when they exit the ‘suicide opening’ door.

The problem with the Mk IV units is their rarity because of the long arm versus the standard arm length. Only a few cars used the longer arm model. The model number stamped on one of my arms is SF35 and the arm length from pivot pin to the end is 8 1/4", whereas the common model SF80 and similar, is about an inch less, and is the style used on the Mk V and most cars. One arm of mine has a part number of 539941 moulded in it. The SF 55 is similar to the 35 but has a slight difference in the circuitry for the warning light.

There must be an increasing market across the world for having new arms moulded (or 3D printed?) for attachment to the fulcrum boss. This needs an enterprising fan to come up with the ways and means. Note that the festoon bulbs are special slim types that should just slip into the groove, and he can supply these too. If you have to force them in, they are the standard diameter bulbs and the heat from the side contact will eventually embrittle the plastic, and the prolonged side pressure will cause cracking or crazing. There are l.e.d. ones made now but I don’t know if their size is right, however they will not have the heat problem. Some of these are also self-flashing but obviously not in time with the flasher can, which does not really matter.

Just a few other hints about operation. The current is very small and therefore relies on good contacts. The current path goes to the flexible wire which is soldered to the spring finger inside the lens. The seat of this eventually develops mild corrosion. I have overcome this by tinning the circular seat with solder. The earth return then is through the chromed cover and the contact face of this at the bulb end needs to be kept clean and with the bulb having good pressure against it. The spring finger can be bent slightly to help this. The next failure points in the earth circuit path are at the hinge area, where the sides of the cover must bear against the (clean) sides of the fulcrum boss, and at the hinge pin to the body.

@John_John1: sounds like a job for ya!

Hi Peter,

Peter Scott has them fitted to his SS. I have them for the MKIV and MKV. I understand now why they would be easily broken by alighting passengers! Thank you as always for the additional information.

Yes, 3D printing would be a great solution.

Best wishes,


Holy Mackerel! :scream:

I wonder if he could repair my lenses if I posted them to him? Might be cheaper? I’ll contact him and ask.

Thanks you, Peter.


Thank you Polti. I think the one you describe is for a MKV?


Hi Peter,

I contacted him and this is part of his very informative reply.

"This is an 8 1/4 inch one AND it is the much rarer of the types of hinge pickup … The Sf35 is the same size buut the lenses are incompatible as the sf35 is the normal wired method… this is a contact type.

In addition , all sf 34, 54, 40, (7.25) … 35, 55 (8.25), are (unlike sf80) full lens/arms. Unlike sf80- you can’t just replace a plastic simple lens. The lens has a metal spine and the hinge built into it… so the entire arm must be unpinned and replaced. Of this sort of armed trafficator, the sf34 makes up about 75%, the sf40 about 15%, the sf35 about 8% and the sf55 about 2%

sf35 8.25 are generally yellow, sf55 are generally orange, but as i said quite rare.

Expect to pay at least $100 each for good ones

*You could consider changing to sf35 as a whole. The only reall difference is in the hinge… BUT I seem to remember a strange “isolation” used in some Jags… ie. not a chassis earth return… can’t remember. I’m sure it would be easy enough to improvise around that. *

You are far more likely to get complete sf35 than any parts for sf55."

There you go.



Yes, there is a weird bit of wiring in the Mk IV trafficator circuit. If you follow the circuit diagram, there is no earth return connection shown for the interior lights or trafficators. Power to a trf. passes through to the opposite side trf. solenoid via the interior lights, and not to the trf body. I have made this assumption on the premise that the diagram, though quite crude, is fundamentally accurate. There is sufficient current drop on the output to not power the opposite trf. Can someone please explain this wizardry?

It seems to just show this circuit in a closed loop back to the fuse block with some reliance on the resistance in the other solenoid. Somewhere I have a document that mentions this and if I track it down I’ll post the relevant words. I haven’t rejuvenated mine yet to test this but the insulation system around the cable connectors at the bottom of the solenoid would be critical.

There are various items where no earth symbol is shown on the diagrams but here’s a MkIV one that shows an earth return.
image image

Thanks Peter, that looks more logical. This shows a three-wire harness but mine is only two. The trf earthing can be done by a mounting screw but the interior lights will need the back feed to earth at the trf. I note the two internal ‘switches’. I am aware of one which trips the bulb after the arm is raised but can’t reason the other.

Thanks again

Just like the headlamp dipping solenoids there are two coils. One generates a magnetic pull strong enough to move the armature but having moved is switched off leaving the a second coil that draws less current to hold the armature in the activated position.


Thanks, that’s a great help. My father said that headlamp solenoids sometimes cooked up and you would see fumes coming from the lamp shell. I suppose the starting coil stayed on and just overheated.

Hi Peter,

Yes, I think your suggestion re overheating solenoids is probably correct.


:))) Looks like I need to expand Jaguar range in my garage :slight_smile:

Just to add to this, I have two units, one is SF 54 J, the other is SF 34 J, both are 225 mm long (2 7/8 inches), that fit the MKIV.