Well I didn't need a new BCM after all!If the relays on the BCM main board were butchered it's likely that the board was also butchered in an attempt to repair/replace. I know for sure that while removing the relays it's rather difficult without a proper heat gun desolder/resolder station with precision temperature controls. For example I use an Aoyue 968+ station for electrical repairs.
Just know that there is an IMMOBILIZER on nearly all Tiburons outside of the US. This means if your car has an immobilizer, your BCM needs to match the ignition key module or your car will not start. Additionally the 2007-2008 immobilizers are a little different and somehow perform a VIN check against the ECM over the CANBUS. You can work around the VIN check by using an older ECM from 2004-2006 so that's an easy work around if you can find a matching BCM and ignition key module. Otherwise a sure fire way to get around the immobilizer issue is to source a US spec BCM and ECM so you can delete the immobilizer.
I ended up taking the BCM to an auto electrician (who I highly recommend) who repaired it...yay!
Some info that might be useful to others...
- If the indicators are stuck flashing then the problem is likely not with a relay. The common faulty relay issue usually results in the indicators being constantly lit as the relay is constantly closed.
- My issue was caused by water damage to the BCM, apparently this is quite common and can be caused by blocked drains - either the scuttle panel or the sunroof, both can result in water inside the cabin often in the footwells.
- My issue was with the relay driver on the BCM, I can't say how common that is though.
- It's quick and easy to remove the steering cowl and disconnect the switch to check the problem isn't with the switch.
- If you're in the UK then Mike at Pro-Lux electronics in Billingham is the man for BCM diagnostics and repairs.