Voltage leak in Landcruiser 80s

When you say "in-line". how exactly do I do that?

I suggest the following.
Use a multimeter that will measure DC durrent up to 10A.
Remove + battery lead.

Put multimeter 'in-line' with battery lead by connecting red multimeter lead to + battery terminal and black lead to the + battery lead.

Measure the current.

Remove all fuses.

Measure the current as above. If it is now zero - good - you can now isolate the circuit that the current is flowing through.

In turn, push the multimeter leads into the holes for each fuse. Get + and - right first time if possible. Doing this at the fuse box means less running back and forth to the battery if its only you doing it.

Measure the current for each fuse hole. One or more of them will have a current flowing through them. Measure all - just to make sure you get them all.

Fault find on those circuits that have current flowing where it shouldn't.

In my case I would then get bleep off and give it to an auto elec. but at least you've narrowed it down and is good practice for the bush!

Have fun..

Rob.
That is the way that I would do it but with one exception.

Use a test light also, preferably something that has a reasonable current drag, say a stop light bulb, so you actually put a load on the test circuit.

I say this because I had a similar but reverse problem with my Engel fridge. All checked O.K. with the volt/multimeter which showed a current present of 12 point something or other volts registering.

Hours later I still could not figure out why my fridge did not work.

It was purely by accident I picked up my test light, and when I put the probes in, the light did not light up, I then I tried it again with the multimeter it showed that I had power.

As it turned out, the problem was in the cig lighter where the wires had broken, yet there must have been some contact to make a reading on the multimeter.

I think you will also find that most modern vehicles do have at all times some current drainage that is normal. Electric clock etc. or what ever. My wife Pintara, the electric fuel pump is alway active, and to change the fuel filter I have to remove a battery terminal.

Just my 5 cents worth.

Regards