2010 Peugeot partner brake lights

[Brucey89]

Hi, I noticed that the 3 brake lights were not working on van, I checked fuse all ok. Swapped out brake switch which made no difference. Checked bulbs all ok. After checking passenger side brake bulb, when I turn ignition on brake/tail light is constantly on. Won't go off even with brake switch disconnected. It's now reading economy mode activated when starting engine.

1. Would a bad earth or faulty wiring cause these issues?
2. If I disconnect bulb will it stop power draining from battery until I can get it into mechanic. Van won't be driven until going to mechanic just don't want battery going flat.
3. Anything else I'm missing or could try?
Thanks

[paul_c123]

Has it gone from faulty (none of the brake lights working) to a different variation of faulty (one brake light on all the time)?

[chrisch77]

Unfortunately it sounds like a body control module glitch; my 08 Berlingo has random electrical issues from time to time such as intermittently refusing to power the LH rear indicator, or putting the wipers on when the ignition is off…. After the indicator issue I followed the wiring harness from BCM to the rear light cluster and proved there was no continuity issue in the wiring. Next step was to remove each plug in turn from the BCM and blast both sides with contact cleaner. Then the same in the engine bay fuse box and ECU. So far so good but I’m not convinced I have done anything and the issues are inside the module.

Everything is powered by the body control module, that also does the immobiliser so it’s not a straightforward job to replace it.

[Brucey89]

So after messing about with old brake switch there was no continuity, then there was. So I checked middle brake light 1st and if I moved cables the light came on and then went off. No key in ignition at this stage.
Then I got multimeter out an was getting 12v-13v at cable supplying bulb.
Decided to change reae passenger brake bulb 1st and was putting cable back into van to secure light cluster and the light came on.
So no key in van no lights on, put key in and turn to ignition but not to start the left passenger brake light and taillight is lit. Saying economy mode active, van starts etc but middle and driver side brake lights are not lighting up.

[Brucey89]

paul_c123 said:

Has it gone from faulty (none of the brake lights working) to a different variation of faulty (one brake light on all the time)?

Yes after moving harness around, even with brake switch removed brake/tailgate will stay on with key turned on