Imobiliser problems

[Paul G]

I have disarmed the alarm on my 4runner, when the Dome fuse is out the truck runs fine but when i plug the fuse back in the Hazard lights start flashing and the car wont start, its a standard toyota unit and the tech guy at my local toyota garage said there should be an earth wire atatched to the body close to the plug he told me to disconnect,however i cant find it.
I need to get this sorted very quick as the truck is booked in for an mot this week and if the Dome fuse is out the rear fog light doesn't work, please can anyone shed some light for me, cheers Paul