Rear brake lamp fault

byeo · 2 Jan 2017 at 19:06

Yesterday I was driving with the Mrs when a notification popped up on the dash, Rear Brake Lamp Fault (or words to that effect), pulled up and confirmed the left brake light wasn't working.

Picked up the correct bulb this morning, changed it and works fine. Got in car an hour or so later and when I started the car up the same warning message popped up again, checked all lights just to make sure a different one didn't go. All fine, I decided to change the other rear brake light as I got a pack of two bulbs, still same issue, brake lights work fine, message is still displaying when I start the car up. After a quick search online some people suggest making sure I acknowledge/read the message so it's not listed. Done this and still stumped. Is there anything else I can check before I take it to Ford to have a look at bearing in mind I'm only used to basic car maintenance.

The car in questions is a 60 plate Mondeo.

Thanks.

manjuice · 2 Jan 2017 at 19:11

Did you replace a halogen bulb with an LED one?

byeo · 2 Jan 2017 at 19:16

manjuice said:
Did you replace a halogen bulb with an LED one?

I don't think so, this is the bulb I picked up:

http://www.halfords.com/motoring/bulbs-blades-batteries/car-bulbs/bosch-380-p21-5w-car-bulbs-x-2

blueboy2001 · 3 Jan 2017 at 01:17

I've got a 2010 Mondeo and had intermittent brake light faults reported, but only when I touched the brakes. It would happen about once a fortnight, but the lights worked fine.

I swapped both bulbs for Bosch items and it's not happened again. One of the bulbs the element looked a bit misshaped which I suspect was the root cause.

Have you got the Convers+ color display or the orange LCD? If it's the former, have you got a red or yellow warning icon showing, or is it just in the Messages section?

If there's no icon I suspect if you ignore it it may well disappear after a long drive when the brakes have been used a bit. If it persists, you could try removing the battery for a bit and reconnecting. You could probably clear it manually with an ELM lead and ForScan. I wouldn't bother taking it to Ford.

If the icon is still there I'd swap the bulbs and clean the contacts with some alcohol or contact cleaner and go from there.

byeo · 3 Jan 2017 at 06:22

blueboy2001 said:
Have you got the Convers+ color display or the orange LCD? If it's the former, have you got a red or yellow warning icon showing, or is it just in the Messages section?

If there's no icon I suspect if you ignore it it may well disappear after a long drive when the brakes have been used a bit.

I've got Convers+ colour display.

Bit of an update, started the car up this morning to go to work, warning message appeared again (cant remember seeing any red/yellow icons) went around back of the car and no lights were showing. Indicators and brake lights worked fine but apart from the light illuminating the reg plate, i was in complete darkness at the back.

Had to drive to work, expecting to get flashed or pulled over, once I pulled up I sit in the car checking my phone, decided to start the car again just to see, I didnt notice any message pop up as I jumped out to check the rear lights, low and behold, they were now working. Like I said I didn't notice any warning messages as I got out right away so I'll check again later when I head home. If I get no message and everything is working as it should I'll leave it at that. If same thing happens toomorrow then I may just let Ford take a look.

DavidS14 · 3 Jan 2017 at 06:48

Are the rear clusters on multiplugs ? If so check that they are fully connected and look okay. The warning messages may be linked to a voltage drop caused by poor connections ?

byeo · 3 Jan 2017 at 07:49

DavidS14 said:
Are the rear clusters on multiplugs ? If so check that they are fully connected and look okay. The warning messages may be linked to a voltage drop caused by poor connections ?

The rear brake light bulb and indicator bulb pull out together, if that's what you mean. :confused:

blueboy2001 · 3 Jan 2017 at 13:19

Sounds like a loose connection. Strange it's on both sides though. Check the grey plugs that connect the wires to the bulb holders are fitted securely. I'd remove the bulbs and clean the contacts to be sure as well.

pepsilol · 3 Jan 2017 at 13:23

Sounds like dodgy wiring and the original bulb wasn't actually at fault. If you have the original bulb still to hand test it.

Liquid_Entity · 3 Jan 2017 at 13:32

I've been having loads of bulb problems with my 08 Mondeo lately. Must be the weather.

byeo · 3 Jan 2017 at 15:28

blueboy2001 said:
Sounds like a loose connection. Strange it's on both sides though. Check the grey plugs that connect the wires to the bulb holders are fitted securely. I'd remove the bulbs and clean the contacts to be sure as well.

What would I clean the contacts with :confused:

or will a good blow do the job ?

byeo · 3 Jan 2017 at 16:49

pepsilol said:
Sounds like dodgy wiring and the original bulb wasn't actually at fault. If you have the original bulb still to hand test it.

The bulb had definitely gone.

byeo · 3 Jan 2017 at 17:48

It's now fixed, the "new" bulb I put in yesterday must have been not 100% (I'm guessing) as I went down to Halfords to fit another one just to be certain with myself, fitted it, brake lights work, side lights work and no error message. Thanks to all who gave possible solutions.