Dodgy light switch?

[Scimher]

Having collected 'Little Sis' (late '64 1200 conv.) from my wonderfully kind friend, Mike, who has repaired the trailing arm mounting & driver's floorpan..(see relevant thread).. I drove her to my equally good friend's garage unit. He was impressed by what had been achieved. As the light was going, I decided to switch the sidelights on before driving off......nothing happened!! I jiggled the knob (as the actress advised the bishop to do!!) & kept twisting it on & off.......the lights came on & stayed on. The column stalk seemed to be working fine. I drove up to the local chipshop to get chicken & chips, started her up & no lights! This time, no amount of fiddling worked!!

As I was only about a quarter of a mile up the hill from where I live, I took a calculated chance & set off down the hill (reasonably well lit...) The Law of Sod ensured that about a dozen vehicles were coming in the opposite direction whilst we were sat motionless waiting to turn right; a rather forlorn RH indicator winked away, with me praying that some huge juggernaut (of which many use this road...) wasn't going to choose that moment to come thundering down the hill & steamroller us! Of course we had several headlight flashes from the oncoming vehicles, who, no doubt, were wondering whether either of us were fit to be on the Queen's Highway!!

To add insult to injury, after I breathed a sigh of relief, having finally ducked into the parking area, I was just about to switch off the engine, when the headlights came on of their own accord!!! I know she has a sense of humour, but I was not impressed with the little minx, that's for sure - & after all that surgery from her Uncle Mikey, as well..!!

Soooo, ladies & gentlemen, if you are still with me, what is the likelihood of the switch being defective, as opposed to one of the three? wires having a bad connection in the teminal? I've had a look on ebay & there is a used switch assembly deemed suitable for a Herald, MGA, TR2/3....I had a good look at it & it seems to have the same brass connections at the back that a household plug/switch has...(It ain't cheap, that's for sure!!)

 

[RobPearce]

It could be the switch but there are plenty of nasty little bullet connectors and potentially rusty or loose Lucar spades in the circuit too. If the lights had been flickering on and off while you jiggled then I'd say very likely the switch but it sounds like the jiggling had little effect until the lights "decided" to work, possibly coincidentally.

[Rutty]

The switch did fail on my Vitesse last autumn but as Rob says it could be a connector. You could bypass the switch and that would prove you problem.

 

[Scimher]

...Thanks for the response, guys - the funny thing was that once the lights had come on at the garage...(I used the headlights)...they didn't blink or flutter once on the way to the chipshop - a distance of 2miles.......But, as you say, I guess that it's just a case of checking & cleaning connections....Isn't the switch what is known as a 'rheostat' item - I think that just means 'complicated'...!! 🤣

[glang]

My Vitesse master light switch recently failed but its the 3 position push pull type which I think is different from yours. Anyway I opened it up (love old gear as that would have been impossible with a modern item) and its very simple. Two flip flop spring loaded contacts and found one had broken springs so I removed it to make it just a two position switch.

This works fine as originally when pulled to the first position it powered the exterior lights and then the second position also turned on the dash lighting whereas now theres just one switch position that operates all the lights together. This only required a changing around of the connector positions on the switch but of course means I wont be able to drive at night with the instrument lights off....     

[RobPearce]

Quoted from Scimher-

Isn't the switch what is known as a 'rheostat' item - I think that just means 'complicated'...!! 🤣

I wouldn't expect it to be a "rheostat" - which is an old name for "potentiometer" and would imply variable dimming. The WSM appears to show something similar to glang's Vitesse (and mine), although I believe there was a change from screw terminals to Lucar spades at some point.

[Scimher]

Thanks Rob - just me getting confused then......(sadly, not unusual, these days!...😆)

[Scimher]

...I used her today with the excuse that I needed to take some stuff to the recycling depot, about 3miles away, in the warm spring sunshine. All good - when I got back I tried the light switch as she was nosed into a wall & I would be able to see the headlights if they came on..............they did, first time with no problem! I'm just wondering if, with the warm, dry weather, that it may have been damp, a touch of oxidisation, lack of switch use.....etc., etc. We'll see how we go on with it.....

[Scimher]

Well, after a long period of behaving herself, light switchwise, the problem has re-manifested itself - but worse, this time! I think I will have to get my professional friend, Andy, to check currents etc. with his multimeter to see if it really is the switch...