Volvo: 1992 240 fuse change, amp fuse, type fuses

Question
my 1992 240 has ceramic type fuses and last year I has a problem with fuse #12 (8 amp) and my mechanic upgraded(?) the fuse to a plastic housing newer fuse
(10 amp with heavy duty fuse holder soldered to the # 12 terminals).

My questions are
1. does going from a 8 amp ceramic to a 10 amp new type fuse cause any problems? Car ran great for a while then wiring related issues started.
2. should I replace the whole fuse panel and stay ceramic?

Many other related questions..........but this is fine to start with.

THANKS

Answer
Replacing a fuse with a larger one is never a good idea, because you're just avoiding the real problem, which is usually a short in the circuit, a bad ground, or a malfunctioning device on the circuit.  A large fuse can allow unsafe current levels to go through wiring designed for lower amps.  This can cause issues in itself.  In your case, however, the wiring related issues you mentioned could also just be caused by the original problem avoided with the larger fuse that is now getting worse.  To really solve the problem, you need to seek out the problem on the #12 circuit and repair it.  When you do, you should be able to go back to the factory specified 8 amp fuse.