With the fuse box removed it and the fuse can be inspected. This fuse box was removed because excess heat caused the fuse box plastic to melt. This allowed the copper fuse connection on the left to be pulled to the right within the body of the fuse box. Eventually the two copper sections would touch, bypassing the fuse.

The old, damage box is shown on the left while the replacement box is shown on the right.

See how the fuse is bent in the middle as it's left-side connection was pulled to the right.

In this case this was caused by the timer on the glow plug relay no longer functioning after the glow system on the older style glow plug system after it was converted to the fast glow plug system. The glow plugs stayed hot, with 12V going through the fuse, while testing the window regulators on this car.