Hi all,

A few years ago my grandfather's Transporter had an issue whereby the hazards, horn and wipers would go off when the ignition was turned on. This was diagnosed as a faulty BCM, which was replaced.

Fast forward to 6 months ago, and the battery started "randomly" going flat. He then realised that the hazard lights were going off randomly, and pushing the button turned them off for a short time, then it would happen again. Thus, this was the cause of the battery drain.

We put it into two local garages, the first swapped the hazard light button but that didn't fix it, and the latter was recommended as a VW and electronics specialist. The van sat at his for 2 weeks, and at the end of it his verdict was "it hasn't done it whilst we've had it, and nothing came up on the diagnostics test". Of course, 2 nights after taking it home, it did it again!!

At the end of my tether, I installed one of those battery isolators from Amazon, but that now seems to be intermittently faulty and rather than put another isolator on, I'd just like to fix the issue once and for all.

To me, this sounds like another case of a faulty BCM, but is there anything else that it screams out as to anyone?

In addition to the hazards going off when idle (locked or unlocked, doesn't make any difference), it also has occasional moments where (when driving) the doors will lock uncommanded and also the wipers will refuse to turn off, and then turn off but won't park at the bottom of the windscreen.

If it is the BCM, then is it just as simple as swapping it over, or does that need a "professional" with a computer to do? If so, then I'm at a loss as the only one of those locally is the one with whom I was less than impressed.