I have been trying to figure out what is wrong with my 98 lesabre limited, when I turn the key I get no noise from the fuel pump like I usually do and the starter does not make any clicking or noise of any kind. All I hear is a relay clicking behind the glove box. It only clicks once when I turn the key to ignition and once when I try to turn the car over

When I try to hook my computer up to get error codes it cannot connect

I have trickle charged my battery to 100%
checked all of my fuses
checked relays to the best of my ability but im not sure im checking the right one or the right way. Just making sure the terminals with the fuse looking thing are normally closed which they are

Before this happened it has always started on the first crank until the last time, it would start but then stall right away, after trying it 3 more times it started and ran perfect and got me home but now it will not start

Im wondering if its the ecm but have no clue how to test it and do not want to start throwing parts at it

Thank you in advance for tips and advice