Headlamp flash not working

[1969Mk3Spitfire]

As per title, the headlamp flash doesn't work.  Side lights, main and dipped positions all work but nothing from the lever to flash the lights.

 Is this likely to be a switch issue? Any checks to confirm before going in search of a replacement?

Thanks in advance.

[Adrian Cooper]

The first thing to do is check that you have a live unswitched supply to the column stalk. There is a purple wire that supplies the flash circuit and it joins the other blue/white and blue/red wires at the base of the steering column to run up to the stalk. The purple wire may have worked loose from the bullet joint at this point or it may have broken between there and the fusebox but a quick test with a bulb or a multimeter will tell you if this wire is the problem. If you have a working supply then the flash contact in the stalk may need cleaning. If you unscrew the cowls you should be able to see the contacts without too much contortion. The contacts can burn but I would bet that it is simply a loose connection further down the steering column.

Good luck

Adrian

[Colin Lindsay]

Check that you do actually have a headlamp flash - early Heralds, for example, don't, so their switch has three wires, but later ones do and so have a four wire switch. The switches are interchangeable so yours could have been swapped for a non-flash model due to a fault or other problem. (Easiest way is to pull it and see if it rocks back to a flash position; others won't) or as Adrian says remove the cowls and count the wires.

[1969Mk3Spitfire]

Many thanks, very helpful.

There are indeed 4 wires from the switch assembly including a brown with no connection. There’s also a live purple without connection. Both have connectors fitted.

I can now see that the wiring diagram shows brown to purple. The brown wire is a lot smaller diameter compared to the purple so didn’t “look right” but removing one of the bullet connectors and pushing the brown into the purple has solved the problem.

The encyclopaedic knowledge on here is great 👍