G'day people, thought I'd share this one.
Took us a while to find issue and fix, got there in the end.
First issue, cabin fan stopped working, car still drove for a few days.
Second issue, car burbled and stalled, sounded like fuel starvation.
Car now cranked but did not start, no fan either.
Suspecting electrical gremlins at first, removed BCM, inspect and cleaned.
Cleaned all earth points in boot and under bonnet.
Unplugged every harness accessible , cleaned and put back.
Swapped relays , checked all fuses.
Car still not starting, suspecting dead BCM or ECU issues.
Changed fuel filter, car ran for a couple hours, then stalled again.
Finally checked fuel pump for current, it was getting power.
Replaced fuel pump, car still did not start :(
Then swapped relays back over ( the two at the bottom of fuse panel in passenger foot well )
FIXED
It looks like the faulty fuel pump was causing a short or some electrical disturbance to the relays. They are both next to each other, sharing the same earth etc.
The top relay controls power to dash controls, bottom one is fuel pump.
Car runs fine now , so does cabin fan.