Yes, butt splice connectors are rated up to the 600 volt insulation range.

You can buy a butt splice kit from the auto parts store, it will consist of different size butt splices and the crimping/stripping pliers. Choose the proper size butt splice, strip a length of insulation off each end of the wire to be joined roughly half the lenght of the butt splice, put the wire in each end of the splice and crimp. Once the connection is made wrap the splice with electrical tape.

A butt splice must be crimped with the proper tool and proper die to get the full compression that the splice needs. In most cases the barrel butt splice should be the same manufactures name as the tool that is used to crimp it. Bolt cutters are used just as the name applies for cutting bolts. Bolt cutters have a cutting knife edge and when used to crimp butt splices there is not enough contact of the surface area on the splice. This knife edge also weakens the splice, as the material of the splice is separated before enough pressure can be applied to tighten the splice to the wire inside the barrel.

There is nothing wrong taping a broken wire. As long as the wire connection is made with an approved mechanical device, the splice can be taped. With broken wires, usually the conductor is put together again with a butt splice. On larger size conductors the butt splice is just bare metal. This type of splice has to be tapped. The code rule states that the tape insulation must be brought up to the insulation value of the existing insulation factor.

Why bother? Just remove the wires from the inertia switch, and splice them together with a butt connector.