Wiring caught fire

[Robsey]

Just another thought.

You have me second guessing myself.

I am still 100% certain about -
Black = ignition live,
Brown = ground.

My seed of doubt is that blue and white.
Is it blue with a white stripe, or is it pale grey with a blue stripe.

Silly I know, but grey with a blue stripe is for instrument lighting (dimmable illumination).

Without seeing exactly where in the loom you are, and being able to physically or visually trace the wires myself to their terminations, it is very difficult to guarantee that I am barking up the right tree.

[Robsey]

My advice would be to look at every section of the wiring for each circuit.

The brake lights is super simple.

Red wire with yellow stripe from fuse 8.
Goes to the switch on the brake master cylinder.

Other wire from brake master cylinder is red with a black stripe.

This changes to black with a red stripe and goes out to the rear light clusters via the engine bay junction box

The light clusters will each have their own brown earth wire.

That is it.
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The indicators are more convaluted due to having a flasher relay,
Two supply voltages into the hazard switch,
(Red and white from fuse 9 = Battery live for the hazards,
Black and blue from fuse 11 = ignition live for the indicators.).
And a separate indicator stalk switch.

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There is a chap on ebay who does laminated colour wiring diagrams for these vans.

If you are good at reading and understanding the ladder diagrams, then these laminated sheets may be a useful resource to get your electrics sorted.

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Dependent upon your own confidence and skill levels, you could completely 're-wire' both circuits with fresh wires.
Rip out the old wires, and fit new.
As said - the brake circuit is super simple and just requires wires and spade (lucar) connectors.

What ever you do...
Make a note, keep a record and put clear labels on any changes that you make.

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Final thought - EARTH CROWNS !!
Have you cleaned these up?
Lots of adverse electrical gremlins are caused by poor earthing.
It is not unheard of for voltage to seak alternative routes through other cirtuits to find a path to ground.

Just saying...

[Robsey]

Another thought....

Firstly - do the hazards work?
Yes ?

And... is it ONLY the indicators and brake lights affected?

Using a process of elimination.

If hazards work but not indicators.
And if other ignition live circuits are also affected, then this points to a faulty ignition live feed.
Perhaps the ignition switch.

If the hazards do not work, then maybe the hazard switch is defective. Or as you previously inferred the flasher relay may be goosed.

For wires to become burnt, it would require a current higher than the wire is intended to handle.
Possibly a short circuit.

If you post up a rough location, then there may be club members reasonably local to you who could assist in identifying your problem.

Fortunately, ignition switches, hazard switches and flasher relays are not stupidly expense compared to most T3 parts, if you wish to go down that route.

[Oldiebut goodie]

Going back a couple of post - shouldn't the hazard switch be fed from a permanent live not an ignition live. Seems wrong to me that you have to have a key in when you have broken down, usually the first thing that you do in an emergency is take the key out. I haven't perused the wiring diagrams but it just seems wrong.

[Robsey]

There are two feeds

One ignition live for the indicators.

One permanent live for the hazards.

On some later vans, there is also another key-out position so that the indicators can be used as side markers at night.
Just like most passenger cars since the mid-80s.