1995 Jaguar XJ6 won't start

My 1995 Jag XJ6 started up great every single time, even in snowy, frigid weather. All of a sudden it just simply wouldn't. All the dash lights come on, the windows and doors all still work, but no turn over. I had a mobile repair guy come out and check it. He said the battery's got plenty of charge. He can get it started with under the hood doing whatever you mechanics do, so apparently the starter's good. When the key is turned on he says he doesn't hear the fuel injector motor come on. Since both starter and injector systems are suddenly affected, he wondered if the alarm system has something to do with all this. I don't have a remote clicker, just keys. He's not gotten back to me.I've been researching and have found the valet switch and am going to look for the inertia switch today.(I've not been in any wrecks though) Grasping at straws.I'm a woman and this is not my area of expertise at all. Any suggestions before I have to have it towed 75 miles to the dealership? It's been sitting for almost 2 months. Is there some starter disable system I can over-ride? Some trick with the alarm? Thanks in advance.