Anyway, I have a suggestion that I don't see listed here (in case the problem should return).
Do you have a trailer electrical connection on your van?
From my experience (non-transit, but think it would still apply), if the trailer electrical connections rust and short circuit or abridge, if say two random cables/lines end up touching somehow, this can cause all sorts of weird behavior to any lights that are part of what gets directed to a trailer, such as brake lights or even fog lights.
Worth inspecting for anyone ever getting similar symptoms
Also, there is earth on both sides left+right for the rear lights, in case you find one and it looks good, then rule out the earth before checking other side
Cheers, MvGilvray


