Rear high level brake light problems

[matzki]

Hi guys.

 

I have a Mondeo MK4 (year 2007 hatchback).

Today I decided to change light bulbs in high level brake light.

Over time all five off the bulbs were blown. Last one blew a week ago. So I opened everything up, bought new W5W bulbs. Changed then and put everything back together. Only to find out that HL brake light still did not work.

Every other light in and on the car works fine. All fuses are checked. 

I can see that only two wires come in the bulb socket at one end. The other end has a socket also, but I have no wires to put in there. Multimeter says that they run 12V all the time. But if I press the brake, then it goes to zero (0 Volts). My logic says that it's ment to check if the voltage runs though or if all the bulbs are blown then it send back an error. And before there was a error on my display. Saying " Rear Break Fault" or something like that. So now that I have put new bulbs, it does not give me an error like that. Therefor the car knows I have working bulbs in. But somehow bulbs don't light up when I press the brake.

    

Any ideas? Maybe someone has had a similar problem.

I havent tried to connect the car to a laptop yet. So maybe thats the next step.

 

All the best

 

Matzki

[matzki]

Hi again.

I tried few more things. I checked for the ground in the wire the goes into bulb socket. All checks out. Ground was good. So the issue was not there. Looked at some youtube videos and as the youtube videos showed I checked the wires inside the boot. Nothing was corroded and all connections were good. And side brake lights did not go out when all the plugs were disconnected. Boot light, lock, wipers stopped working. When connected - all previous works again. So they were not connected with brake lights. Only thing I could not check was to connect car with a program and check for errors etc. Just did not have the software and equipment.  

So I went for the easy way out. Took off all the plastic, connected a new wire from a working brake light to high level brake light. Hid the wire behind plastic and now it works well. I kept the formal wires in the HL brake lights socket, so the car knows that electricity goes through and does not show an error on my dash. 

Maybe in the future I'll unplug the new wire and then connect to a computer. But for now it works for me.

 

Matzki

[isetta]

In case anyone else has problem and reads this. You do not have to have this light working for mot, it says it’s not a failure if the light has been permanently disconnected.  However from a safety point of view it is desirable to have it working.  The fix here is just the kind of thing I would do. If you can’t solve the problem, work round the problem