Location of Ignition Relay
 

I have the issue with intermittent no start, no click, no nothing. I don't get the weird thing with the visor mirror light, but more and more frequently, I first turn the key and nothing happens. Usually, it would start right up on the 2nd try, then might go a week without any problems at all. Recently, I had times where I had to turn the key 5-10 times to get it to start. I picked up an ignition switch, which I will put in today, but I also have read about the issue being due to a relay for the ignition. I saw a video for an E46, where the black relay was behind the fuse panel in the glove box, but I haven't been able to identify the relay and location for my 2006 E53 3.0. Can anyone show me where it is at? Thanks!

Do you have another key and does it do the same with both? Starter relay is built inside the EWS module (immobiliser).

https://www.pss-autosoft.net/diagram...E53_EA146B.htm

For test purposes you could short wiring on EWS module pins 1 and 2 (thickest wires, black and black/yellow) to bypass the relay.
If the key transponder is not recognised the car will still not start (will crank) because EWS does not allow fuel injection by DME (engine ECU).

I keep meaning to switch to my other key, just to keep batteries charged on it if nothing else. I will try that out today (gives me an excuse to go for a drive!)

You might check the battery cable connection at the starter.