ISTR it's accepted practice to put a reverse-biased diode in parallel with the relay coil - otherwise you get an arc across the switch contacts when they open again (giving them a very short life). Maybe this either just wasn't present in the SD1, underspecced for the job, or just prone to failure for some reason?
(I remember the same fault being common in Triumph Stags, but the same switches were used in various Jags, so there's at least more scope for getting spares from a junkyard)
Lucas did indeed make relays with built in diodes, but didn't use them in this case.
I've just looked up the wiring diagram for the Series I cars and they didn't use relays. They also used a different design of switch. The later switch is as I said also used without relays in some other models so is probably rated at 20 amps or so. The problem in the Series II cars is the contacts get oxidised - possibly through drawing too *little* current.
Yes - those window switches and design of switch was common to many BL cars. Perhaps others too. The nacelle switches on the SD1 were only used on it and perhaps some Land Rover products.
Good ol' Lucas ;) Although in all honesty I didn't have *that* much trouble with their parts - but given their reputation, lots of folk did...
Ouch. They must have to handle quite a bit of current - any idea if they had some sort of mechanical arrangement to cut power at the appropriate points, or did they rely on detecting motor overload and switch off that way? (former sounds like a disaster waiting to happen if someone gets their head stuck in the window :-)
Maybe, although I've only heard of the Jag ones being common (I suppose not that many BL cars actually had 'leccy windows).
I've found a lot of plastic deteriorates on cars of that vintage, too - it goes from black to a funny grey colour, but even if cleaned up (by removing the surface and polishing) it just comes back in a few months; presumably some sort of age-related break-down in the chemical composition.
I suppose it might get to the point where using a more modern switch and making up some sort of authentic-looking plastic capping is the best route...
It's many years since I've been inside a SD1 - and even then that was a basket-case which we were looking at with a view to salvaging the engine (it had a bi-turbo setup; not sure if that was an after-market mod or if Rover did offer it on original models?)
cheers
Jules
I had a 7 litre SD1 once upon a time
3.5 under the bonnet and 3.5 in the boot
Hmm... that's actually tickling some braincells - was it featured in any magazines?
(assuming you didn't mean that you just moved an unconnected 3.5 lump in the back* of an SD1 once :-)
coming bang...
cheers
Jules
What did it cost you for the hay every week for all those horses?
Dave
They refused to eat it with the 20/50 gravy on it
Made me smile. I had a friend with a 2CV. His engine went pop, we took it out of the car and he went to the garage on a bus to get a replacement!
Well they were the main maker in the UK and car electrics were likely to cause problems whatever the make so most put two and two together to make
Nothing so sophisticated on any SD1. One cutout if you exceed the maximum current allowed for the window wiring. If you hold down the button the motor just eventually stalls. And they're pretty powerful motors compared to today's types.
I meant the generic design. Which included lighting etc switches. The sort used on a Series I XJ6. The SD1 only used these for the windows - push button types for everything else.
Yes.
Trouble is many modern switches are keyboard types and control logic. Which makes for a lot of work if you wanted to use them.
Aftermarket.
I use the SD1 most days I'm not working and invariably someone will say 'I used to have one of those. Till it rusted away.' ;-)
LOL
Dave
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