Hi all,
I’m hoping someone here has either seen something similar or can recommend an auto-electrician who’s comfortable with intermittent faults...
I've tried to write this up as well as I can, but I doubt I have seen every possible failure scenario!
Vehicle:
2020 Transporter T6.1, 4Motion TDI
Leisure battery fitted
The issue:
I have an intermittent electrical fault that is temperature-, moisture- and load-dependent. It’s been going on for months and has resisted dealer diagnosis.
Cold / wet conditions (main trigger):
• Fault often occurs on vehicle wake (unlocking)
• Brief abnormal light behaviour (e.g. main beam flash / DRLs staying on)
• Dash logic dead or partially dead
• Cranks, fires, then immediately cuts out
• Heating the cab/dash area for ~30 mins allows it to start normally
Hot conditions:
• Engine runs, but while driving (town speeds) multiple systems briefly drop out and recover:
– ACC / Front Assist / Lane Assist unavailable
– CarPlay disconnects
– Lower dash (cruise speed / compass) disappears briefly
– Audible relay “thud”
• Clears on its own, can repeat every few minutes
• Long motorway drives in the rain can be completely fine
Load-related triggers:
• Unlock/wake event
• Electric tailgate operation (especially closing)
What’s been done / ruled out:
• Battery and charging system checked
• BCM replaced by VW (behaviour changed slightly but fault remains)
• No consistent fault codes that explain the behaviour
• This doesn’t behave like a sensor, calibration or software issue
At this point it feels very much like a marginal wiring / ground / connector integrity issue, possibly moisture-related in the dash/BCM area, but I’m struggling to find an auto-electrician willing to take an intermittent fault on!
Questions:
• Has anyone experienced anything similar on a T6.1?
• Any known loom/ground issues in these vans?
• Can anyone recommend an auto-electrician (Surrey / SW London / wider if needed) who is good with this kind of thing?
Any pointers hugely appreciated, even just “I had something like this and it turned out to be X”.
Thank you advance!
I’m hoping someone here has either seen something similar or can recommend an auto-electrician who’s comfortable with intermittent faults...
I've tried to write this up as well as I can, but I doubt I have seen every possible failure scenario!
Vehicle:
2020 Transporter T6.1, 4Motion TDI
Leisure battery fitted
The issue:
I have an intermittent electrical fault that is temperature-, moisture- and load-dependent. It’s been going on for months and has resisted dealer diagnosis.
Cold / wet conditions (main trigger):
• Fault often occurs on vehicle wake (unlocking)
• Brief abnormal light behaviour (e.g. main beam flash / DRLs staying on)
• Dash logic dead or partially dead
• Cranks, fires, then immediately cuts out
• Heating the cab/dash area for ~30 mins allows it to start normally
Hot conditions:
• Engine runs, but while driving (town speeds) multiple systems briefly drop out and recover:
– ACC / Front Assist / Lane Assist unavailable
– CarPlay disconnects
– Lower dash (cruise speed / compass) disappears briefly
– Audible relay “thud”
• Clears on its own, can repeat every few minutes
• Long motorway drives in the rain can be completely fine
Load-related triggers:
• Unlock/wake event
• Electric tailgate operation (especially closing)
What’s been done / ruled out:
• Battery and charging system checked
• BCM replaced by VW (behaviour changed slightly but fault remains)
• No consistent fault codes that explain the behaviour
• This doesn’t behave like a sensor, calibration or software issue
At this point it feels very much like a marginal wiring / ground / connector integrity issue, possibly moisture-related in the dash/BCM area, but I’m struggling to find an auto-electrician willing to take an intermittent fault on!
Questions:
• Has anyone experienced anything similar on a T6.1?
• Any known loom/ground issues in these vans?
• Can anyone recommend an auto-electrician (Surrey / SW London / wider if needed) who is good with this kind of thing?
Any pointers hugely appreciated, even just “I had something like this and it turned out to be X”.
Thank you advance!
