Dead short D/S park lights and dash

[Sly]

Giday Crew , have a issue with fuse 16A 5 amp blowing with out turning the ignition on ???
Its a 98 tdi300 130 and I am working of wire diagram for a 97 defender. As per the diagram side lights front and rear are removed , trailer plug removed , head light removed and left hand relay from fuse cluster also removed.
This 130 also has no Relay dim dip behind the dash front.
I have cleaned the main earth point on the fire wall / under bonnet , is there another earth point I have missed .

[DazzaTD5]

If its blowing a fuse its not a poor earth.

If its blowing a fuse straight away it means its a dead short to earth, I suspect a chaffed live wire on the body somewhere is the likely cause.

A very simple way of finding a direct short to earth is using a "load bank" (see picture below) its 12V light globes wired in parallel with two spade ends that will fit in the fuse slots. You remove the fuse and connect the load bank in place of the fuse.

You will then find if its a small short the globes will glow a small amount, if its a direct short to ground the globes will glow brightly. you will then need to work your way along the offending circuit wires moving/working them back and forth, when you see the globes change in brightness or go out completely you have found the area where the short is. Keep in mind the short maybe either onto another circuit (but an earth circuit) rather than the body or a shorted component connected to the circuit (so dis-connected components to isolate them).

The advantage of using this method is it wont melt or burn out the wiring (as the globes are taking the load of the current), it is a clear visible method (over using a resettable fuse)

Keep in mind a "short" that blows a fuse is simply a completion of a circuit without any load to slow down the current flow. As in a circuit is simply: Active (power) > Load (a component) > Earth to ground.

Regards
Daz