Car won't start

The disco won't start. its a 300 tdi, P reg. Power is getting to the starter motor but there's just a whirring noise. I don't think it's engaging. The electrics seem to be playing up a little (Alarm system). Can it be connected? I've also noticed a Heat/Burning smell latly. Smells something like over cooked brakes or clutch (mines an auto). Any info on a remedy. Thx Ian

Check your earth cables.

Check connections to starter motor and like redhand said check all earths (to body etc). smell might not be connected but for now just check main things like oils. (gearbox etc)

Sounds like kentucky fried starter motor to me.

Would I be right in saying that the ignition switch can be a little bit sticky at times?