Changing from Positive to Negative earth

[Roli]

Hiya

I'm hoping someone in the know can help me with this one...

(I have to confess to simply being the messenger on this, so please don't laugh if I sound like an idiot! )

We're about to change our moggy from positive to negative earth so that we can fit an electronic ignition system (not been a good few months). Can you tell me if it actually as simple as swapping the battery connectors? and what about the regulator unit?
If we do this, will it make the starter motor spin the wrong way?

Any suggestions or tips gratefully recieved

Thanks
Roli

[bmcecosse]

Yes - unfortunately the starter runs wrong direction - so the engine will then run backwards, giving you 4 reverse gears and only one rather slow forward gear.
All very unsatisfactory - and not worth it just to fit 'electronic' ignition! Just stick with good old points - unless very high power motor - standard point ignition is very simple and copes admirably!

I was of course joking - if you REALLY feel you must have negative earth - then yes - swap the battery connections, and the coil connections. You need to polarise the dynamo by 'flashing' it with a wire from the +ve terminal of the battery - and touch it to the small terminal on the dynamo a few times - it will spark slightly as it reverses the residual magnetic field in the field windings. Also should open up the petrol pump and clean the points - same for dizzy - clean the points or fit new. That's all there is to it! But - I wasn't joking about staying with points ignition - it's fine! Electronic is just not worth the hassle.

[LouiseM]

Details of how to change to negative earth are in the Technical Tips section here:

http://www.morrisminoroc.co.uk/index.php?page=322

[grilk]

Thanks for the quick (and funny ) replies to my wifes post! I have descided to regiter my self, as I think I'm going to spend A LONG TIME on this forum trying to get Borris back on the road.
I was curious about a Pos to Neg earth conversion, as I have now had 2 supposedly reputable mechanics telling me there is no spark and that the battery is in the wrong way round! The confused look on the RAC mans face when he tried to test the battery was amusing!
I think I need to go Neg earth if I fit an alternator (the car is only used for very short comutes and the battery isnt charging)
Thanks - Trev

[PSL184]

Hi Trev - Yes you will have to change to neg earth if you fit an alternator as well as some other wiring mods to the regulator box, however, I would understand why its not charging before changing anything.

[bmcecosse]

And it's certainly not the reason for 'no spark'!
The 'RAC man' must have been easily confused - but then , they usually are!