I just installed a heater core on my 2006 LR3. After getting everything back together the car turns over but will not start. All my dash lights/icons come on including the flashers. The flasher button will not turn off the flashers only turning off the car at the ignition will turn off the flashers. Any help out there guys?

 

I have little experience with the LR3 but I will say that in the D1, the flashers come one after the inertia switch has been triggered. Worth a shot.

Also and perhaps more relevant, check for water ingress behind the fuse box which may be there because you replaced the heater core in the first place. I've read they don't like to be wet in that area.