Can someone help please , L 322 3.0 td6 2004, Auto, I have a starting issue or more accurately non starting issue key turns to proper position but nothing engages no clicks , have read screeds about this , so know need to locate the starter relay , looked in the black box box behind the battery and only one relay there and it’s light brown , I’m told it light green. Also what does the lead off the battery do labelled battery squib .