Again, i must point out that i am not familiar with this type ,but most large aircraft have a minimum of 6 WOW (weight on wheel) sensors.Usually 2 on the nose gear and 2 on each main gear. Some systems might only use the nose gear sensors to detect WOW, other systems may use the main gear sensors or both nose and main.
With regards to the anti collision lights(ACL) being on , i have known some A/C to have the beacon(red) manually switched and the ACL to be automatically switched of the WOW system.