I always smile when I see people saying disco tfer box best mod for defenders!

Any chassis wax well worth adding 25 ish percent hydraulic oil, makes it creep better and keeps it soft for ages.

Sadly that is an open ended question on the d3, low vs causes multiple issues, only way to be sure is new alt and maybe new battery. Always worth popping over to the disco3forum and doing a search for your issues, think need to sign up to search, but well worth it. The alt is told what to...

Looks like the head gasket might have gone awol, easy ish to do on the 200/300. Look down drivers side (I think) of the head and you will see tangs on the head gasket, this denotes its thickness. The 300 were prone to head gasket failure as the water pump is mounted so high the slightest drop...

Low volts causes all sorts of problems, d3 are well known for alt issues causing special programme and suspension issues. I can tell you during the winter mine runs high 14s to low 15s, summer high 13s to mid 14s, and it has been that way for 11 years.

The damp is what does it, does not even have to be soaking wet.

Covering it with the carpet will be what caused the issue in the first place, gets wet then stays wet.

If it is dropping to lo 12volts whilst driving then I would say you have an alt problem. I have never seen mine go under mid 13volts. New alt must be Denso (I think) anything else will cause issues.

I would say that looks quite normal for a 14 year old defender that has never had any love.

The D3 can run up to 15.2 volts when it needs to, generally higher charge rates means the battery is on its way out.

What is on the underside of the bonnet?

So the battery has 14.6 volts before you start the engine?

Nope not master cylinder but the brake shoe return spring. Are you CB or CV naster cylinder?

If it is dry then adjusting it up is not going to help matters, change it whilst you can as you just know it is going to **** the bed at the most dangerous moment.

On my D3 the bloody things kept leaking, would be okay for days or weeks then the diesel smell started, in the end new leak off pipe assy fixed it for good, 150 quid Iirc! It was the leak off pipe to front rh injector that was the issue.