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MG MG Y Type - positive to negative

hello i,m thinking of changing my yb to negative earth has anyone any views on this and would anyone have details on how it,s done
thanks john
jr dennis

John

Is there any particular reason you want to do this? It is reasonably straightforward to do ... but you have to ask yourself why you might want to do this. Do not just do it because "everything else in the world is the other way round".

One of the reasons often miscited for this being a "good thing to do" is that it makes the car less prone to rust. That is simply not true. Steel will rust at the same rate whether you pass current through it ... or not - at least as far as our lifetime goes.

So, is there another reason - you want to fit a CD player, cell phone charger, nitros boost pump, bouncing suspension pump, electric windows, ghetto blasting sound system etc.? Otherwise, frankly I would bother.

That said though, some people want to do this and I was looking through some old stuff the other day that was covering this so I may well dig it up again and put it in the Technical Centre so it is on file - for completion's sake if nothing else.

If you need this sooner, let me know and I'll move it up my workload.

Paul
Paul Barrow

John

Here is a link to the article anyway - http://www.spritespot.com/Downloads/Positive%20to%20Negative%20Ground%20Conversion.pdf and I am in the process of getting permission for us to add it to our site.

Paul
Paul Barrow

Providing there are no components which is polarity sensitive such as a radio or electronic ignition [ensure there are no suppression diodes fitted] etc, it is only a matter of reversing the battery connection and then touching the small stud field terminal of the dynamo with a +ve supply [it will spark]. I converted my YA and 105e Anglia many years ago and more recently my TF. More recently there has been some discussion regarding the ignition coil connections, but my cars have run for years with no degradation in performance. I stand corrected but as far as I understand the coil is not polarity sensitive at least my ones are not.
B Mellem

O! I nearly forgot, the ammeter connection must be reversed otherwise it will show a healthy discharge when the engine is started and the lighting load a charge.
B Mellem

I would also get a couple of signs saying "This vehicle is NEGATIVE ground" for the inside and outsite of the battery box. I seem to remember MOSS Motors carry these in their MGB Catalogue range so this can be made to look professional. This will also help any one working on the car who is used to expecting these cars to be POSITIVE ground - like I would for instance.

Paul

Paul Barrow

paul and mr mellem
thanks for your reply
still can,t decide i am also thinking of fitting an alternator and remote servo i would appreciate your comments
john
jr dennis

John

You cannot fit an alternator without converting to Negative Ground, so that is a fairly easy one to cover.

As to fitting a servo, my personal opinion (which others may feel free to contradict) but if your brakes are properly and regularly adjusted, your brake shoes in good condition, your fluid changed regularly, you drive within the design parameters of the manufacturer (and dont try to be silly with it) and bear in mind that other motorists and pedestrians have seen UFOs and space Aliens before they saw a Y Type, then the original braking system of the Y is more than adequate to stop you.

In all of my years (is it 12 already) since I got my Y, it has never failed to stop me adequately and in a safe distance ... without a servo, and on cross-ply/bias ply tires. And yes I do drive it hard, and yes I do drive in the rain too.

Like I say though - this is just my personal opinion.

Paul
Paul Barrow

An excellent article on fitting an alternator can be found at http://ttypes.org/ttt2/ford-alternator-conversion-on-a-t-type. The principles and steps are easily mimiced on a Y Type.

Paul

Paul Barrow

One thing to note if you change your Y or YB to negative earth is that the battery leads dont fit as the round posts (on the type of battery fitted) have different diameters. This is the main reason I did not bother to convert my YB as I had bought new leads for the positive earth system.
D MULLEN

If its any reassurance I have several times in the past thrashed my YA over the Alpes with a caravan on the tow bar, and never experienced brake fade although I always treated the descents with care especially the mountain passes. John you are the proud owner of a fine motor car!

Bryan
B Mellem

Hi Paul, that link gets me a 404 error "not found on this server".
Remo Peter

This thread was discussed between 30/10/2010 and 02/11/2010

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