Ignition light stays on after switch off

[Welshk9]

Just rejoined the Morris community after 10 years, and bought another Morris, (it's great to be back)but this one has a niggly little problem, i wonder if anyone can make any suggestions.
Alternator and oil pressure gauge fitted by the last owner, car starts and runs like a dream until you stop and switch off, the indicator light stays on, start and stop the car several times and then the light will eventually switch off, leave it on and walk away and you cant start the car again when you need to.....
I have replaced the regulator, looking as if it was the problem , but it still persists, any ideas anyone for some testing??
Regards
Steve

[bmcecosse]

Welcome to the forum.....there is no external 'Regulator' with an alternator installation....(unless a very ancient Lucas AC 11 has been fitted...) Are you sure it's not a dynamo? Whatever it is - you certainly must not leave it with the light on. If necessary - disconnect the battery, If it IS a dynamo - then the points in the Regulator may need cleaning - disconnect the battery before attempting this.....

[simmitc]

Quite often when an alternator is fitted, the old regulator box is left in place to act as a junction box - it serves no other purpose at all. The most likely problem is that a diode has failed within the alternator. If you're into electronics, then you can disassemble and fix yourself, otherwise just buy a new unit - that's usually as cheap as trying to do an exchange.

[Welshk9]

Wow now that is a prompt reply, thanks guys, really appreciate your helpful comments. The joy of having a Moggie again... Will do some investigations, but i am always open to suggestions before i go under the bonnet at the weekend. Many thanks Steve