Ignition light stays on

[cococola]

When I drive my moggie the ignition light stays on.the battery is ok but is it possibly the dynamo please?

[DAVIDMCCULLOUGH]

It will either be the dynamo has stopped charging due to worn brushes or the regulator box has become faulty. I wouldnt drive too far with it not charging.

[mike.perry]

Or the fan belt is slack

[bmcecosse]

Or missing....

[alexmcguffie]

or a wire disconnected...

[simmitc]

Or shorted to earth.

[cococola]

Ive popped a spare dynamo on today and it is still the same.
The fanbelt is fine and tight enough.
Are there any checks that I can do on the regulator box and any potential wires not connected please?

[bmcecosse]

First check is the wires connected to the regulator - and to the dynamo. The regulator is quite well described in the Workshop Manual - if you don't have one - Google for a free download!

[Sips]

I have exactly the same issue, but the dynamo is less than a year old so I hope it is not that!

Following the haynes manual I have checked all the wiring and cleaned all the connectors which looked fine. The only thing I can see that is non standard is that the contacts between F and D have been connected together. It seems not to make a difference when in place or not.

Whilst running my battery is reading 12.4v so there is an issue with the charge somewhere!

Does anyone have any thoughts on this or a way to test the dynamo properly?

Thanks!

[bmcecosse]

F and D connected together is an emergency measure - and the dynamo will be pounding out max charge all the time - destroying the battery on the way.....although I would expect more than 12.4 volts!! Is the battery dry inside? You need to look into this urgently.

[Sips]

So this is a bodge to bypass the voltage regulator? The battery is a sealed unit so I am unsure if it is dry or not but is seems to be fine and not getting hot etc. Am I best to remove then bridge between the 2?

If the Dynamo is shot could this be protecting things? is there an easy way to test the dynamo? The voltage across the terminals of the Dynamo is about 11.4v if this means anything. Do Dynamos just stop working or do they gradually reduce in output?

Thanks!

[bmcecosse]

The standard test for a dynamo is - remove the wires and the fan belt. Join the two terminals together with a length of cable and then firmly touch that cable to the NON-earth terminal of the battery. The dynamo should spin round as a motor.