XC90 2007 Starting issues

[slaphead720]

Hello all.

My first post so apologies if its in the wrong location.

For a while now I have been having intermittent starting problems on my XC90. Since it started last year, I have had the starter motor replaced and now the ECM refurbished, all with no joy.
I can still start the car every time with a lead from the starter/solenoid to the battery positive post under the bonnet, and then it runs without any issues.
It has been into a main dealer but again with no definate answer, just it might be the ECM, followed by the price of £2000+ and then either 10mins labour or 10 hours.
Which is why I decided to try a replacement ECM, with the option to return if it didnt work, and it hasnt.
Im running out of ideas.
Would the antenna ring cause problems like this?

Thanks,

Alan