Clicking with ignition off?

Ok, so I went to start an old Disco yesterday, the battery I tread granted was flat so I hooked up and tried to jump the car, which didn't work. There was power going to the dashboard.
But with the ignition off I had constant clicking. Ignition on, no clicking and didn't even attempt to turn over.

I have since had the battery on another Disco and it starts that car fine. And holds charge. I won't lie I am a relative novice, so any ideas??

Thankyou

Sometimes when jumping a vehicle if the car/battery that wont start is so flat the good battery is also pulled down and may not provide enough power.
The clicking is probably a relay trying to spring into life but again there isnt enough power.
Of course the indicators could have been on and you didnt notice?

Don't think they were it was just odd that the clicking which sounded like relays, was making the sound with ignition off. I will try a good fully charged battery when I get the chance. It's only a filthy H reg one I want to off road. Thank you...

On the older 200 discos when they have had a hard impact the hazards come on automatically.

But surely the clicking of relays would stay on with the ignition on?

lynall said:

On the older 200 discos when they have had a hard impact the hazards come on automatically.

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Much the same as any other vehicle that has central locking past and present

RichyMondy said:

But surely the clicking of relays would stay on with the ignition on?

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That would depend on if the relay supply was ignition switch controlled.

discool said:

Much the same as any other vehicle that has central locking past and present

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That I dont know, but can vouch for the one on the 200 disco when I may have accidently driven into to a large hole and come to a ratehr sudden stop