New here truck not starting

[derrh2]

Hi peeps hope you can help I've got a 2007 nissan navara d40 I've just drained the automatic transmission fluid and also taken out and cleaned the valve body from the gearbox I've put it all back together and now it won't start I thought it was the battery but I just had it on charge for about 6 hours and re fitted it but no go not even the clicks you get associated with low battery charge