Ignition light stays on when engine running

[Dominic]

Hi folks

Just started the Morris for the first time in 3 months, after a lot of work - MOT tomorrow. The works I did had nothing to do with the ignition system, being brakes and suspension, along with some welding at rear.

When switched on, the ignition light comes on as usual. When the engine starts, it stays on, glowing brightly, with no change in intensity relative to engine speed.

Fan belt is ok, dynamo physically spinning when engine running.

Brushes replaced on dynamo about a year ago.

Control box likewise replaced, but just cleaned contacts on it to make sure.

Apart from headlamps being changed, no wires were disturbed during the work, have checked all wires being connected as normal.

I did charge the battery up yesterday to make sure enough charge for starting.

Any ideas please?

Ohh, presumably this light problem won't affect MOT? All lights apart from this work as normal!

Cheers

Dom

[PSL184]

Assuming the light is working corectly and not shorting to earth somewhere then the only other reason for the light to be on is that the battery is not charging. Check connections from dynamo to regulator and regulator to warning light and also put a meter across the battery with engine running. If you get at least 13.5 volts ish the battery is charging from the dyno, if lower, ie around 12 volts or less then its not charging. The light won't fail the MOT but the car may not start to get you there !!!

[grumpygrandad]

possible brushes sticking,, light not efect mot as long as all other lights work eg, main beam dip warning light,, grandad

[Dominic]

Just tried testing the voltage, 12.5ish with engine and everything else switched off, 12.39 with engine running at approx 1000rpm. Sounds like dynamo to me in that case. Do you all agree?

[PSL184]

Yes, dyno not charging sufficiently - light working as intended. Check brushes are free and not sticking as Grandad says..... You can lube the sides of the brushes with a smear of copper slip if required.

[Dominic]

Seems like my luck is in! I just spent a few minutes running the car, manoeuvering out onto the road and reversing back into the garage (naughty naughty!) so I could have it facing out to adjust headlamp beams. There again was the nice familar flickering glow at tickover! It must have been sticky brushes or general build up of crud from 3 months of idleness!
Thanks for the advice chaps!

[PSL184]

Most likely a build up of crud on the stater ring which has worn through as its spun round and been rubbed by the brushes. Just check battery volts with meter to be sure

[bmcecosse]

You didn't reverse the polarity when you were charging the battery by any chance ?

[Dominic]

no- red to red & black to black. All seems ok in that dept. now at least!

[bmcecosse]

Good -just a chance you had the battery out, and put it in wrong way round.

[Dominic]

nahhh - lazy here! I just disconnect the cables prior to charging. It worked perfectly today by the way.

[bmcecosse]

Sticking brushes then!

[moke-man]

Spooky! I have a 1964 2 door saloon. The ignition warning light stays on all the time with apparently no detrimental affect. That is apart from annoying the .... out of me. I think everything is working Ok. Have I been a silly Moke-man and simply connected the battery polarity incorrectly. Without me giving the game away what should it be? Cheers all, Tony

[bmcecosse]

Welcome aboard. Is the system charging the battery when the engine is running - should rise to 14 volts DC - measure with a cheap multimeter from Maplins. If not - check the polarity. Red light staying on means a current drain from the battery to the dynamo/alternator - and in the case of a dynamo indicates it is trying to run as a motor and will soon burn out/flatten the battery -so definitely don't leave it like that - take a battery connect off, quick!