Negative Earth.

[exlkrs]

Finally gave in and changed! Can fit a period radio cassette now.
There's so many stories/doubts/myths around this, and a dearth of info if you want to keep a dynamo, so simply -

Disconnect smaller F terminal from back of dynamo.
Disconnect and reverse battery ( I needed a new positive terminal)
Reconnect battery.
Attach wire to battery pos, and 'flash' (you see sparks) the other end of this wire 3/4 times to the dynamo terminal you exposed earlier.
Remove wire. Reconnect wire you removed earlier to the dynamo.
Reverse the 2 connections on each side of the coil.
Start up, job done!

***IMPORTANT SAFETY TIP*** (See photo)
This many have brought the now positive terminal to the left in close proximity to the battery clamp bar.
I cut a notch out of the bar here to put more distance between them and added a little insulation into the notch.

Safety first!

neg.jpg (407.27 KiB) Viewed 898 times

[geoberni]

Welcome to the Dark Side, according to a certain breed of owner.....
You're right, there can be an issue with just switching the battery around when you first change, depending on which battery retaining bar your car has.
There were 3 different ones used over the years, along with 2 different designs of tie rod.

Also fitted with an insulating rubber strip, even though the terminals were to the back??

Finally gave in and changed! Can fit a period radio cassette now.

But if it were truly period, wouldn't the radio cassette be Pos Earth to...

Incidentally, according to the Parts List illustrations, your bar might be upside down, or just not one of the originals

Battery strap.JPG (124.55 KiB) Viewed 880 times

[exlkrs]

You try finding one! More chance of seeing Elvis riding a Unicorn down your street. Actually went for a polarity switchable 8 Track, but it just blew fuses. Gave up and changed! My bar is as it came and definitely not original, has a strip of wood underneath (hence self tappers) to help it maintain the correct angle to grip properly.

[geoberni]

You try finding one! More chance of seeing Elvis riding a Unicorn down your street. Actually went for a polarity switchable 8 Track, but it just blew fuses. Gave up and changed!

The only ones I've ever seen have been very expensive and still only sold for 'repair'..
Mine was already Neg Earth when I brought him, but it took me nearly 2 years to realise they had forgotten to change the Coil connections, so I was getting through Spark Plugs, probably as they were overheating because of the spark going the wrong direction.

[svenedin]

Welcome to the Dark Side, according to a certain breed of owner.....
You're right, there can be an issue with just switching the battery around when you first change, depending on which battery retaining bar your car has.
There were 3 different ones used over the years, along with 2 different designs of tie rod.

Also fitted with an insulating rubber strip, even though the terminals were to the back??

Finally gave in and changed! Can fit a period radio cassette now.

But if it were truly period, wouldn't the radio cassette be Pos Earth to...

Incidentally, according to the Parts List illustrations, your bar might be upside down, or just not one of the originals Battery strap.JPG

Yes definitely the dark side but I can see why people do it if they want electronic gizmos. I don’t have or want any gizmos so positive earth my car stays.