intermitent cranking/ stutter start

[keylessauto]

hello all! Have a 2005 v50 2.5t vehicle intermitenly cranks stops and re cranks without releasing the key. Check engine is on with ecm-5000 crank sensor and intake cam lock release valve stuck code. Found when the starter cuts out it has no power at the ignition lead coming from the starter relay. Checked to see if power was being lost at relay at the time of the stutter but it wasn't. Determined that the ground portion of the relay is being lost. According to the wiring diagram the ground comes from the ecm during cranking. Because i also had a crank sensor code. Verified wire intergrity and signal to ecm are good. I thought I nailed it finally by removing the battery plus connection at the starter off cleaning and replacing one of the ends that looked corroded. Also replaced the ground terminal for the same reason at the engine/transmission connection. vehicle started 30 times with no issue after that so I put everything back together and then it did it again. FML FYI New ignition switch installed and new crank position sensor installed.

Thanks in advance!