Negative earth around the time of the most famously catastrophic rustbuckets (70s being the stuff I'm thinking of).
Yes, people discovered that some form of galvanising works wonders. I was pleasantly surprised a few years ago to see that some paint chips on the wings weren't rusting at all - they still aren't.
Not sure about your dates. I had a MKIV Cortina (T reg - 78?) and a'79 Princess which were both positive earth and I thought my wifes Maestro was. I didn't think mainstream manufacturers switched over until the mid 80's. Agree totally about the galvanising. I have bare metal on the bonnet of my
406 where it was stone chipped at least 5 years ago and it is still shiny. At nearly 12 years old and that funny multipack paint I haven't persuaded myself to do anything about it yet.
Others will be able to give better answers, but I've found bits on the web saying eg MGBs changed in 1967. Minis in 1969?
The first page I found on the Cortina MkIV said it had negative earth. I know my Maestro was -ve earth, and though that was a late one I'd be very surprised if there were any +ve earth ones. Ditto for the Princess.
Rolls Royce never changed to positive earth and their 50s cars rusted with the best of them.
Galvanising and filling body cavities with wax is the reason modern cars last longer.
Usually when alternators and ICE became standard. Although there were some positive earth alternators and radios.
That corresponds to my recollection. Once alternators happened negative earth was in.
Lots of people flipped the polaraity anyway: before electronics a quick zap with the battery across the dynamo field coils and wire the battery up backwards.
We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Invisible Man saying something like:
To keep my old bangers going in my youth, I was a virtual scrapyard inhabitant. It was a common sight to see six and seven year old cars in there with terminal corrosion. No wonder underbody protection became a major selling point for private purchasers.
We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Tinkerer" saying something like:
If they were, somebody had messed about with them. They sure as shit never left the factory like that. The last mainstream cars I had direct experience of with positive earth were the Moggy 1000s, and they were just a continuation of what they'd been for years. By the late 60s, early 70s just about everything made was negative earth.
I only kept my 1978 Renault 20 for a little over two years, and there was a surprising amount of surface rust. They even seemed to build in one weak point: the way they installed a bit of chrome trim on the hatchback cut the paintwork. I made a study of them whilst on holiday in France at the time, and most exhibited the same problem.
Chris
Got through a lot of kurust and jenolite in those days. Dad's 1960s Cortina had a hole through the top of a front wing 3 years from new. Friend's 66 anglebox had rusted through the side of a front wing by 69.
And don't forget the coil polarity. Other snag is permanent magnet motors were becoming common around this time, so check for correct operation of heater fan and wipers.
Looks like my memory is playing tricks, I thought neggy earth went on longer. As to rust, I remember a chap at work with an 1100 that was less than three years old. He noticed what looked like a smudge on one of the bumper bosses and tried to wipe it off - his hand went right through - the metal had rusted away and just left a chrome skin.
There are hose shops in most towns due to all the hydraulic stuff that needs fixing: car places not much more than tat shops these days.
S
Agreed and though it grieves me to say it, Halfords is now your friend, (buy their shares).
Not after about '63-'64
That was the development of monocoques, not earth polarity: Shit design in the case of Ford (water traps everywhere, especially the foam-filled Cortinas), shit paint if it was a Fiat, or shit unions if it was BL (who to be fair, didn't ever rust as badly as the rest - although everything else fell off first).
ROTFL! Halfrauds is s**te. There should be independent car parts shops around which are much better.
They did, Dave: the early post-war cars - Silver Dawn, and Silver Wraith, and MkVI and R-type Bentleys -were all positive earth, and they tried heaven knows how many strange ways of bonding dynamos and radiators to body and chassis and each other before they reverted to negative earth with the Silver Cloud / S1. I've just converted a MkVI to negative earth, and will be doing the same to a Silver Wraith next time the fuel pumps have to come off (they are replacements, with diodes).
Excluding cars acquired for spares, or to sell on immediately, but including projects that were sold before completion, my car list is:
MG TC MG YB MG MGA 1500 Coupe MG TA Austin Mini Van Ford Anglia Van Austin Cambridge Estate Morris J4 Triumph Spitfire MGA MG Magnette MGA 1600 Coupe MGA Twin Cam Triumph 2000 Austin Maxi Auto Ford Transit Luton Morris Minor van Triumph Toledo 1300 Austin Maxi Commer (Dodge) Van Morris Marina van Austin Metro 1.0 Morris Ital van Austin Maestro Austin Metro 1.3 Land Rover 109 Station W Toyota Tercel Volvo 245 Citroen BX17D Vauxhall Astra van 1.6D Austin Metro Peugeot 305 estate Vauxhall Astra van 1.7D MG Midget MkIV Peugeot 205 Vauxhall Astra Estate MG MGB MG SA Rover 218SLDT Range Rover V8 lpg MG MGB Austin 10 MG Midget MG MGBGT Land Rover 109 Wolseley 1300 Lanchester 14 MG YB MG TC Range Rover Peugeot 106 Bentley Mk VI Bentley Mk VI Bentley Mk VI MG MGA MG MGBGT Range Rover 200tdi Range Rover 300tdi Auto Vauxhall Astra G estate Rolls-Royce 20/25 Rolls-Royce Silver Wraith Carbodies Taxi
So in all these years, only two Fords (both vans), and one Japanese.
Indeed, plus a generally better approach to avoiding water and mud traps.
You live and learn. I had dealings with a pre WW2 one which was negative earth and owned an S1 Bentley which was too. So assumed they never changed. But as I said the S Series rusted with the best of them.
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