Ignition light stays on when engine is tuned off!

[martyn yates]

Came home late last night, when I tuned off the ignition the invention light stayed on. Turned the ignition back on , engine fired up no problem light went off. Tuned the ignition off, engine turned off but the light stays on. When the key is turned to the on position the light goes out. My car is a 1957 2 door. Any one have any ideas. Battery disconnected to avoid draining it.

[geoberni]

OK.... That's really strange, like Twilight Zone strange....

Tuned the ignition off, engine turned off but the light stays on. When the key is turned to the on position the light goes out. My car is a 1957 2 door.

As it's turning off the power feed to the Coil to stop the engine, it should also be breaking the connection for the Warning Light which is across A1 and D of the Control Box
It literally doesn't make sense, a broken switch can't be the problem since it's working correctly to power and de-power the Coil.
I'd be checking where there's a voltage that shouldn't be there.
Best I can think of is that there's a sticking contact in the Control Box which is allowing the battery to feed across in reverse and to earth via the Fuel Pump, but with enough resistance in the line that the pump isn't operating....
If you reconnect the battery and the light comes back on right away, take the cover off the RB106 and tap it to see if a contact has stuck....
If the light doesn't come on...
Take the cover off, see what position the contacts are, cycle the IGN Sw on and off and see what they do. That's got to be the most likely area for the problem...

[myoldjalopy]

Classic symptoms of the cut-out contact staying on after turning the ignition off. They should disconnect but can sometimes stick. I am assuming you are running on a dynamo. Try cleaning the cut-out contacts with either some thinners, or if that doesn't work, gently with some very fine glass-paper. This is often a problem with the new repro control boxes which are of inferior quality and don't tend to last too long. But even original ones will fail eventually. And do keep the battery disconnected until you have sorted the issue as it can lead to a fire.......

[geoberni]

Classic symptoms of the cut-out contact staying on after turning the ignition off. They should disconnect but can sometimes stick. I am assuming you are running on a dynamo. Try cleaning the cut-out contacts with either some thinners, or if that doesn't work, gently with some very fine glass-paper. This is often a problem with the new repro control boxes which are of inferior quality and don't tend to last too long. But even original ones will fail eventually. And do keep the battery disconnected until you have sorted the issue as it can lead to a fire.......

I'm glad my thoughts were correct.
I've only had my Minor since 2017 so not experienced the problem yet, but electrically it was the only thing that made any sense. I experienced a small number of such strange things working aircraft systems in my early career, sticking contacts and high resistance earth paths are always interesting snags.

[martyn yates]

Thankyou for your swift response. I should have said that I am running an alternator, so no cut out box/regulator. As soon as the battery is reconnected the light comes on, however if the starter is pulled the engine will only turn over but not start. Turn the key and pull the starter and she fires up. Any more ideas ?

[geoberni]

Ahh, could be anything then .... with no standard diagram to follow.
As I've an electrical background, I'd be going over it with a multi-meter and see what I found that didn't seem right.
I'm thinking perhaps a fault with the Regulator/Diode pack of the alternator?
Try disconnecting all 3 white wires at the fuse to see if it's leaking back that way... you've got a supply or an earth where you shouldn't have. An obvious thing to state, but hard to explain it all in writing.
It could even be a breakdown of wiring insulation.
Without being there and examining everything it is headache material.....
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[myoldjalopy]

Unless the ignition is switched on, the pull-start will cause the starter motor to turn, but the engine cannot fire up until you turn the ignition on. All that is entirely normal.
As for your problem, an alternator will combine the functions of a dynamo and control box, so my guess is that the alternator has failed in some way.

[cyrus]

What myoldjalopy said about the RB106 is interesting and although the OP has an alternator maybe it is wired up using the RB106 as a junction box? Mine is and I noticed that if I pressed one of the contacts down it stuck down, there was current flowing. I didn't like the idea of that so bent the contact down well out of the way where it would never be able to make contact. Just a thought...I didn't like the idea of going over a big pothole and a contact being made, though it seems a bit unlikely.

[martyn yates]

Once again thank you all for the suggestions
. I had another look at the car today and noticed that when the engine was running the alternator body was very hot. Slackened of the fan belt to see if the fan was rotating freely, which it was so no issues with the bearings. Took the alternator to a local alternator specialist, who tested it and confirmed a fault within the diodes within the alternator. So new one fitted and the light now only comes on when the ignition is turned into the on position.
So the light on when the ignition was off indicated a fault with the alternator, those clever folk at Morris cars probably did not design it that way but it did point me in the right direction.
Any one in the Birmingham area who needs an alternator rebuilt or tested I can recommend rotating electrics Flaxley road Stechford Birmingham really helpful, tested mine and supplied a new Lucas alternator for £50.

[geoberni]

Heavens knows how a Diode Pack fault was doing that, because I can't understand where the supply was coming from, but it was the most likely thing. What was that quote attributed to Sherlock Holmes.... "when you have eliminated the impossible, whatever remains, however improbable, must be the truth? "

[myoldjalopy]

"the light now only comes on when the ignition is turned into the on position" OK, that's good, as long as it goes out again as the engine revs rise.
I'm sure it will as I couldn't see any other reason than a faulty alternator - and it was tested and found to be so by your guys in Birmingham. Happy motoring from now on!

[oliver90owner]

Once again thank you all for the suggestions
. I had another look at the car today and noticed that when the engine was running the alternator body was very hot. Slackened of the fan belt to see if the fan was rotating freely, which it was so no issues with the bearings. Took the alternator to a local alternator specialist, who tested it and confirmed a fault within the diodes within the alternator. So new one fitted and the light now only comes on when the ignition is turned into the on position.
So the light on when the ignition was off indicated a fault with the alternator, those clever folk at Morris cars probably did not design it that way but it did point me in the right direction.
Any one in the Birmingham area who needs an alternator rebuilt or tested I can recommend rotating electrics Flaxley road Stechford Birmingham really helpful, tested mine and supplied a new Lucas alternator for £50.

Simply removing the connections would have isolated the problem to the alternator? That would have been my first action - to isolate the fault.

Don't think the indicator light should operate anyway - it should be disconnected when the ignition is switched off?.

I recall, from many years ago, a tractor which lost charge from the battery over a period. The drain was traced to the alternator. There being only two options - the voltage controller or diode pack - made the repair a simple one. The diode pack was found to be the culprit and an £8 replacement restored the machine to working order. Back then all three service packs, for the alternators, were that same price.

[myoldjalopy]

Eh? What's the indicator light got to do with it? The OP has only ever mentioned the ignition warning light, which was the issue that alerted him to the problem in the first place..........

[philthehill]

I think that he means the ignition warning indicator light.

[myoldjalopy]

I think that he means the ignition warning indicator light.

Only he knows what he meant....but I've never heard of an 'ignition warning indicator light', which is a bit of a mouthful. I've only known them to be referred to as the 'ignition warning light' - although the Workshop Manual refers to them as the 'ignition warning lamp'. The actual indicator warning light is referred to as the 'direction indicator warning light'.......

[oliver90owner]

I KNOW I meant the indicator lamp, referred to by the OP. OFF, it indicates the system is charging. ON, it indicatesbthe voltage supplied by the charging system is inadequate. Please yorself if the only indicator you understand is a direction indicator. But ‘fo me, there are quite a few indicators, which are helpful to the operator/driver/repairer of any car.