not starting

I have a 1999 Disco 1 and my mom and my brother tryed to start it while I was at school. They unlocked the car and tryed to start it. But when they turned the key to start it the alarm went off. And now it won't start.

I have charged the battery, tryed to jump it, added more gas. Still nothing!

Any ideas???

plip the remote and see what the alarm light does

Ive had the same problem with my 1999 300tdi. Low batterys in the remote dont help. Change them, theyre cr2032's. Resync the fobs following the method on here, easily searched for. And you should have no problems.... My fobs were re set by Challenger 4x4 and the problem is now sorted. If you have the EKA code you can enter via the door and un set the alarm and immobiliser but these will rearm when engine stopped..

I don't have a Key Fob or EKA

How were the doors opened , key or fob? Doesit have factory immobiliser n alarm? How did you used to start it?

Key. It has a factory alarm. This has never happened before.

so how do you turn the alarm off if you have no fob?

mine is a 1994 300 tdi with factory alarm and i can either turn it off with the fob (single button) or just by unlocking with the key then locking it again and then unlocking it and then everything works fine.
your problem could be the spider causing the immobiliser to kick in.

The d1's have an immobiliser that kicks in if you unlock the door with the key.

You need the unlock code that you input using the key in the ignition, you are not going to start the disco without either a fob or an unlock code.

John