Hello, I hope I can offer you some assistance.
When the car won't start are any warning lights showing on the dash? Or is the car completely dead?
Let me know and I'll reply as soon as I'm able to.
all the lights, warning lights, electrics work fine. When you turn the key everything lights up as normal. And you can hear (is it the petrol pump ?) start up as normal.
But when you turn the final click of the key : no reaction.
As I said initially, this can be the case 20 times and then suddenly it starts. But recently it has stubbornly refused completely.
just one other question, does the car have the standard immobiliser, with the small red chip in the key? If so when you turn the ignition on what does the immobiliser LED by the clock do when the car won't start?
Let me know,
Yes I have the tiny red chip in the key. I'm not with the car right now but from memory, the LED lights up as usual and then goes back to flash mode.
I'd need to try again this evening and confirm that to you but I suppose I need to plug the ECU back into the car for that ?!
PS what symptoms would the ignition key mechanism have ?
the ECU does need to be plugged in. When you turn the ignition on the LED should stay on for 3 seconds then go off.
Let me know when you try it.
I will confirm that but I'm pretty certain that's exactly what happens : it lights up for a couple or 3 seconds then goes back to flashing mode.
the LED shouldn't still flash when the ignition is on, let me know.
OK but cannot confirm until around 8pm when I'm back home, sorry.
Good morning Sean,
didn't have time to do the test last night (takes longer to put the ECU back in than to take out !) Will do this evening without fail.
Probably insignificant but the LED is constantly off now without the ECU plugged in. Whether I turn the key or not.
let me know what is happening when you turn the ignition on with the ECU in. Does the LED work at all? Does the engine not turn over?
OK, sorry for the delay. Have this evening reconnected the ECU and retested:
so, prior to inserting the key, the led is flashing normally ;
when I turn the key to position one, the led is still flashing ;
in position II, all the warning lights come on as normal for a couple of seconds, and then the led goes off completely at the same time as the warning lights;
on the final key turn, no start of the motor,dead. And the led is off.
On turning off the key again, after a few seconds, the led starts flashing again.
from the description you've given the immobiliser is functioning as it should. You mention the starter motor, when the fault occurs you need to check the starter motor circuit, check that the small wire to the starter has 12 volts to it with the key in position III, if it does then this would point towards the starter motor itself. If there isn't 12 volts then the starter motor switch circuit needs checking, although the starter relay is operated by the engine management ECU (or immobiliser ECU on very early cars) check that there is 12 volts coming from the starter relay with the key in position III. It would be quite unusual for the ECU to work then fail then work again, it's more likely to be the starter circuit or relay. Also make sure the main earth wire for the engine is OK.
The starter motor relay is in the fuse box under the bonnet.
Start with determining if it is the starter relay or if there is no earth for the relay been provided by the ECU and go from there.
Let me know if I can assist further and I'll reply as soon as I'm able to.
Thank you for this advice. I know the Ford garage who initially took the car in, did already check the starter motor itself and said it was OK. So I'll follow up your idea of the relay and the earth wire - do you have any indicators as to where I find the earth wire : is it obvious to locate ?
the main earth lead is easy to identify, it is a thick black wire usually a bell housing bolt or a starter motor bolt secure it to the engine/transmission.
Let me know if I can assist further.