Afternoon pepole.

Right, i got all the wiring etc finished for the new ECU but when i start the engine up it won't then turn off.

Some thing is keeping the ignition black wire live.

The ignition switch is fine (i've tested and replaced it).

It only stays live when the engine is running (if i simply turn the ignition on then off the wire will go dead as it should).

I've checked everything, I followed all the wires everywhere to try and find out what is keeping the ignition wire live and can't find anything.


Does anyone know if this could happen due to the Heated front screen??
I had a relay in the under dash carrier but then realised the loom had one under the bonnet as well !!!
Reason i ask this is because the blue wire from the alternator goes to this relay!!

Also my rear wiper motor and boot light are not working.

any help would be much appreciated.

Matt.

 

Anyone??

Before it drops over the page

 

might be something to do with the front screen as its only on when engine is running, i think, also i removed my rear wiper motor, and my boot light now dont work, might be related im not sure,

sorry, it kept it on the page if nothing else

 

Havent the foggiest, but least i replyed

 

up for matt

 

For the daytime peeps

 

I think you must have joined an ignition only live wire controlled by the contact key (like it should) to a always live wire coming from the alternator.

 

And the blue wire from your alternator should only go to your dashboard ligth to ignition, and nowhere else ???

If it goes to that relay AND to ignition somewhere (trough dashboard bulb or wherever) you have found your problem.

 

No i've checked the entire system and everything is as it should be.

The only problem i came accross was i had a relay in the heated front screen holder when i shouldn't have.
This is the only relay that uses the alternator power out (other than the main power to the starter motor)

I will try and start the car tonight and see what happens.


The first route i took was to call the alarm installers back as they interupted the ignition wire. They checked everything and there was nothing wrong with the alarm.

 

The blue wire goes to the relay to let it know when the engine is running, so the screen is only heated when the engine is running and can't be used when engine is off (that is the standard Ford wiring)

It does not go to ignition, although it was turning the relay on and that could have been feeding power back to my ignition
The relay should never have been there.
I don't know how these relays work so i can't figure out what it is sending power too.

 

relay shouldn't send power back.

Don't really see what blue wire now Might be that I was wrong.

On my alternator I have + to battery, then the sensing wire through the dashboard bulb to ignition.

is it the same cable ? if so if a diode in the alternator is shagged it could be that battery + is going through the wire to ignition, but then battery light should light up a bit with contact off / engine running.... Should see what wire and where coming from before I comment further, i might just make things more complicated then they really are now