Possible ignition switch problems...

[Tea]

Hi all,

We've just had our second (same thing both times) ignition problem. We put the key in the ignition switch turn the key and the engine tries to turn over, failing, and then once we take the key out the engine carries on trying to start even though we've supposedly turned the car off. The battery eventually discharges and all goes quiet. Once the battery is charged and put back into the car trying to reconnect it is a no no as the circuit is still open.
We had replaced the ignition switch a few months back and then again a few weeks ago when this same thing happened. It seemed to have sorted the problem until today.

Is this unlucky to have had 2 go so quickly or is it more likely there is another problem causing this?

We've also found the battery (which is a couple months old) discharges over a few weeks and the dynamo, according to the garage who did the battery test for us, is charging the battery fine.

Not sure if the two could be related, but just in case

(The car's a standard 1968 Morris Minor 1000)

[bmcecosse]

Very unlikely to be the Ign switch - could be the solenoid, although these are also deadly reliable. Could be wire touching at the Ign switch I suppose. Does your key switch have three positions - OFF IGN Start (spring loaded) ? Also -when this happens - do the Ign Lights (Red and Yellow) in the speedo remain illuminated while the starter is running amok?? You can try a wee squirt of WD40 into the front of the switch.....

[Tea]

We'll check the wiring tomorrow. It is spring loaded. The key doesn't get stuck in the 'start' position, so maybe this would be more likely to indicate touching wires? The solenoid was changed a few months back, although we since found the original one to be working as well.
From what I remember the ign lights didn't remain illuminated. Annoyingly it's not something I can go and try again as once the battery is charged connecting it up sends sparks everywhere :/
Will also give some wd40 a go.

Thank you for the response.


Very unlikely to be the Ign switch - could be the solenoid, although these are also deadly reliable. Could be wire touching at the Ign switch I suppose. Does your key switch have three positions - OFF IGN Start (spring loaded) ? Also -when this happens - do the Ign Lights (Red and Yellow) in the speedo remain illuminated while the starter is running amok?? You can try a wee squirt of WD40 into the front of the switch.....

[beero]

Disconnect the red/white from the solenoid and touch the main battery terminals on to the battery. Does it still try to operate the starter? If so the solenoid is stuck.
If not you are looking at the ignition switch stuck on or a live wire touching the red/white, perhaps in the loom, caused by some burnt insulation. To prove this you could disconnect the red/white and run a temporary wire from ign switch to solenoid to replace it.
Can you use a multimeter and read a wiring diagram?

[bmcecosse]

Good tip about the white/red wire beero !

[beero]

Just noticed my error, Roy is correct, White/ red, not red/ white, that would be instrument lights (Silly me)

[bmcecosse]

Sorry -| hadn't noticed - I wasn't pulling you up on it !!! It IS the test to check if the solenoid is energised. Sounds like it must be - if the Ign lights don't stay on...

[Tea]

The battery is on charge and so I'll try the white/red wire this afternoon. I've got the wiring diagram and as of this morning a multimeter.

Could touching wires be the cause of a slow battery drain or is that more likely another issue?

[bmcecosse]

Touching wires would normally be a QUICK battery drain ! Slow drain could be faulty alternator if you have one.......

[Tea]

How quick are we talking? We drive the car daily anywhere from 4 to 30 miles on a dynamo (VERY rarely in traffic). Would that be able to charge it enough to keep it going for a few weeks or is it more of a few hours drain?

[lambrettalad]

lots of four miles journeys will give the battery very little chance,30 miles will.

[Tea]

Righty, I've just taken the white/red off the solenoid and then touched the battery terminals and it still tries to start. So this means the solenoid is stuck? What should the next step be?

[bmcecosse]

Fit a new solenoid....

[lambrettalad]

change the solenoid or firstly you could take it off give it a good clean ,and try it again

I've got to learn to type faster

snap !

[Tea]

Excellent. We shall find the old one that is still in working order and replace.


Many thanks for the help.

[John.n]

I would remove the lead to the starter and try the solenoid with a wire straight from the power (non-earth) terminal of the battery. you should hear it cleck if all is ok. this would show that the wiring to the ignition switch is at fault.
Regards,
John

[bmcecosse]

Why do this ? The solenoid is clearly stuck closed!!

[Tea]

I'll be changing the solenoid tomorrow. However, after changing the ignition switch a few weeks back it all worked fine for 3 or 4 weeks before this issue arose again. How could changing the switch 'unstick' the solenoid the first time around?

[bmcecosse]

The initial problem may have been with the old Ign switch - holding in, and damaging the solenoid when doing so..... So now - just change the solenoid and see how it works out. Can't see how else it all pans out. Most unusual failure(s) !!

[John.n]

the idea was to test the solenoid and see if some of the wiring for the activation of the solenoid had shorted out. its a simple check and can help in fault finding. its only a suggestion and might help others.

Regards,
John