Hi,

I have some crazy problems with my Mondeo, here goes:

Problem started with fuse for head lights blowing out.
Now I can start the car, turn off the ignition and take key out and it still runs, can`t stop it unless I turn the head light switch, then the car stops as if I turned back the key :S
What in the name of jesus is going on??
There must be some serious fault in a wiring loom somewhere that causes this?

Can anyone give me some pointers on where to look?

Thank you,

 

I suspect there is a poor ground connection involving the lighting system.
Some of the things you can try,
and check(involves loosening and then retightening) all the ground connections you can find right from the battery negative cable on to the multiple places on the sheet metal under the hood , especially those that go to the headlights.
Something else you can try is to uncover the panels that contain the various relays and tap each one of them and see if one of them after being tapped permits the engine to stop running.There is a back circuit permitting the ignition switch circuit to remain active and that relay drops out after you play with the headlight switch.
If you have someone to assist you , after you turn the key off listen and feel for which relay drops out when the light switch is turned on and the engine stops. I believe once you get the headlights working properly the problem should disappear. I ran through a lot of things that I could think of at the time and don't know which one if any will solve the problem.
If none of the above help let us know.

 

Ok, I will try these tips!
Thank you for answering

 

Did some checking around today, couldn`t find anything wrong with the bulbs, relays or the wiring.
I don t have any rear lights now either, not even the licenseplate lights are working.

These are the fuses that blows when
turning on the ignition and the light switch:

Fusebox in engine
F21 Headlamp switch

Fusebox under steeringwheel:
F90 Rear screen wiper
F88 Daytime running lamps relay
F84 Headlamp switch

i have Formidable, but the car has no fault codes stored.
It must be some bad wiring somewhere, don`t you think ?

 

Unfortunately not all problems will set a code in the computer, so some old fashioned detective work is called for.
Does your vehicle have a rear hatch ? If so, are any of the rear lights on that door?
I think they are and you will not like what will suggest next, but you need to trace that wire that goes to the rear hatch and you may need to remove some internal covering to get at it. Starting at the point where the wire goes into the door look for something unusual or broken where the wire flexes. If there is a plug in the path unplug it and see if there is any change. If so, the problem is on the side that has been removed from the circuit. If not , you might need to go back a little further and look for a possible pinched or rubbed thru wire that is contacting another wire.

 

The only lights that are on the hatch is the lisence plate bulbs, the rear tail lights are on the side body of the car.
Yes, I will try and trace the wires and see what I can find.
Thank you.