Yes I had checked all the cables previously. I'll check for the varying voltage again next. What's annoying is that I paid a BMW specialist to tell me what was wrong so that I didn't have to waste cash throwing money at parts I didn't need.. I'm wondering of it could be the wiring from the alt to the computer, I'll check anyway and come back to you.

I've just checked the wire going into the cluster, it looks like someone has been here before as the screws holding the cluster in were missing. Anyway, I'm getting 14v at pin 3. I believe this should be turning off the battery light... New cluster?

It's booked back in at the garage on Thursday, they dug the report out and they say it states 13.6 to 13.8 volts on the old alt, they said that was out of the tolerance for the 4.4i hence why they said it was the alt. I'll see what they say on Thursday. Yes, I fitted the second hand alt which came with warranty.

Ok, took It back to the garage today, they confirmed that the alternator is charging fine so are saying it's the cluster. They managed to fix the ABS trifecta due to the steering angle sensor not being calibrated correctly! At least that is sorted... It's deffo already had a new cluster as mine is reading 157000 klms but the computer was reading 250000 klms!!! He asked if I wanted to have the cluster coded to the car but that would have meant my current cluster would read the true 250k, I told him to leave it. I guess I should now either leave the car as is or maybe source a new cluster, these are new from BMW here at $1300 but again, the new K's would read 250k or I could source a second hand one and have the tamper dot on...