Melted wiring

[DCerebrate]

Now I know that is a long shot. But can anyone suggest potential cause and remedy for this?
Basically I have aftermarket wiring for the Craig Davies electric water pump, a single very high flow fan, and temperature controller unit.
The Cerb (sp6) scraped passed its MOT with an intermittent horn - everything else good.
Next time I used it, I noticed that coolant fan wasn't working - managed to get round this until I could get it looked at by sticking to country roads.
Just been to have it looked at by my local place - basically wiring to EWP and fan were completely melted - though no fuses blown. Seemed to centre around the black plug in photo - which carried wiring to the electric water pump. Possibly then melting the surrounding wires.
Miraculously this pump and the controller unit have carried on working - you can hear the pump working away after the engine is switched off which is its normal operation - but normally masked by the noise of the fan. Forgot to ask the garage whether horn wires caught up in this.
No big flames, thank God!
There arne't any good applies near me that I know of so I think my garage is just going to rewire and add extra inline fuses.

[Penelope Stopit]

If you follow the red leads in each direction there is a very good chance that they will lead you to where they connect to an unfused battery positive, if they don't then try following another colour
This looks to me like a typical amateur wiring job and the circuits haven't been fused correctly

The above is going by what I can see and there is obviously a high percentage of possibility that I am not even close, but it is very likely that an unfused battery positive has caused the burnout

When having the circuits rewired there is no need for extra fuses - Correctly fused circuits is what it's all about

[Rockettvr]

Something that’s found quite often is that with age and all the road crap and water thrown at it that the electric fan can start to seize and draw a higher current than normal. This then leads to the fuse in the fan circuit blowing now and again - after a while this starts to be a ball ache so to stop it blowing all the time a simple bodge is to fit a higher rated fuse
Now you’ve got a fan drawing higher current than normal, a fuse allowing that current to flow, but wiring that isn’t capable of carrying it so it wil eventually get very hot melt the insulation (and anything else that’s in close proximity) and if you’re unlucky cause a fire
Not saying that this is the cause here (although it’s something id be looking for)

[DCerebrate]

Thanks to both, so will be looking towards higher capacity wires, and checking fuses are in place for wires from pos terminals.

[spitfire4v8]

Also i would have routed it all away from that metal pipe. Its contains petrol.

[TwinKam]

Frightening what some people pass off as 'wiring', pros included.
I strongly recommend that you get someone who a) knows what they're doing and b) has a little pride in their work to completely reroute and redo that shocking piece of dangerous se wiring. This time you were extremely lucky to get away with it.

[DCerebrate]

I checked the SPAL website. For a high flow fan, the current can be 'up to' 40 amps!! which might explain a lot.
Repair is in progress and looks as if I will also need a new Craig Davies digital control unit (good piece of kit btw).
Thanks for all advice. Systems will all be checked over at annual specialist service.