Query Re: -ve Earth Conversion

[buellzebub]

Hi All,
Just changed my '65 Tourer to -ve earth following the instructions here: http://mmoc.org.uk/index.php?page=322 and with particular regard to paragraph 8:

" 8 Swap the 2 small wires on the coil over. These just pull off and slide back on. If

in doubt you should end up with the black and white wire connected to the

terminal marked - or neg."

My coil wires were already this way round and according to the diagrams in the Haynes, that shows the White/Black already on the earth side with the original +ve earth set-up.

And here on RogerRust's diagram: http://www.morrisminoroc.co.uk/index.ph ... ic&t=19679, the White goes to the +ve terminal (I assume the diagram shows +ve earth)

Which is correct? Which wire should be on which terminal with a NEGATIVE -ve EARTH SET-UP?

Other than that it all went fine, took 15mins, everything worked and the car started first time.

Just for info, the main reason I converted to -ve earth was that I just fitted LED stop/tail lamps; not 'period' or original I know, but practical and hopefully should never blow.

Thanks for the help

Mick

[alex_holden]

With negative earth, the positive coil terminal is connected to the ignition switch and the negative coil terminal goes via the distributor to earth. I'm pretty sure that wire is black and white.

My Haynes manual agrees that the coil to distributor wire is white/black.

[buellzebub]

Thanks Alex,
I've just put a meter on both wires and can confirm that there is +12 volts on the White wire and nothing on the White/Black. This would seem to confirm that the White should be on the +ve terminal and the White/Black should be on the -ve terminal of the coil.
Cheers,
Mick

[polo2k]

the earth terminal on the coil should have the same color wire as the one leading to the condensor in the Dizzy.

[bmcecosse]

It's the same wire! It may not be marked '-ve' if it's an old coil. It would be SW in the +ve earth car - now that's the one you need to connect to the coil!
BTW - you should check and clean the contacts in the fuel pump and in the dizzy. The 'pip' and 'pit' they both had before will now reverse with the changed polarity - and it's best if you clean them flat or heavy wear/closed up gap may result, leaving you stuck on a wet and windy night!

[buellzebub]

It's the same wire! It may not be marked '-ve' if it's an old coil.
BTW - you should check and clean the contacts in the fuel pump and in the dizzy. The 'pip' and 'pit' they both had before will now reverse with the changed polarity - and it's best if you clean them flat or heavy wear/closed up gap may result, leaving you stuck on a wet and windy night!

Excellent tip!! I hadn't realised that, Thanks.

Mick