Battery drain

Disco 1 300 tdi had a new battery two months ago as it was slow to turn over and it still sort of is ,started fine monday night but its not used every day and the missus wants to take it to work today as we have snow !

Shes been on the phone saying its not turning over and the battery lights on so long story short im going home at dinner time with a huge 632 battery off a combine harvester from work to jump it and il test with my multimeter to see how much charge the battery has but what could be draining the battery so fast ?

Thanks

Alternator?

good that you have a multi. stick it on the battery to measure volts with engine off. then get it started and check again. you are looking for 14.4ish to make sure your alts working.

if the alts working, then you have a real drain. stick multi on 10/20a and discon the neg on the bat. place multi in series with the bat, so one side to the bat neg and the other to the neg wire.

read the current, if it's high, go start pulling fuses until it drops, then you can narrow it down.

don't crank or put large loads on the landy like this else you could fry your multi.. or at least need to hunt for another fuse

come back if stuck

Thanks for the replys ,i found the battery i was supplied was for a petrol disco and didnt have enough cca ,fitted a larger one (after cutting aircon pipes so it would fit) and she starts like a guddun now was -4 last night and started without being heated this morning

I now have an airbag warning light since i moved the sensor but atleast she starts !