I had a pair of Peavey UL-12 speakers in for repair from Barry Barnes of the band Sinnerboy, the excellent Rory Gallagher tribute. (See www.sinnerboy.co.uk). The recently re-established Peavey UK distributor were taking ages to get me some replacement Black Widow baskets so I ended up cancelling the order and getting them reconed at RMJ in Keighley. I sketched out a schematic for the crossover (I have just included the passive setup. There is an alternative connector for active).
The tweeter fuse is a polyswitch or resettable fuse which I replaced with TE Connectivity RXEF040 which opens the circuit at about 400 mA RMS and dissipates excess energy in the 2.5 Ohm resistors and the bulb. The fuses had exploded in a puff of soot which I am sure isn’t meant to happen. The tweeter coils were intact though.