I've been doing some preliminary analysis of my speedo. It's one with the green lead used with a 3 wire Jaeger type sensor (no additional amplifier box). I see the circuit contains an IC labeled 92967 RCA for which I haven't been able to locate a datasheet. If this IC is shot then that's the first problem and a pretty big headache. I haven't disassembled the rest mechanically but does anyone know what's the mechanical setup? Is it a servo motor? a stepper motor? Is there a spring cup like in mechanical speedos? Things to be careful with?
Back to the IC as it is the electronic heart. A couple of possibilities - while Veglia Borletti may have chosen it specifically for this speedo, it's also possible that in this particular time period - mid 80s - they had other speedos for other models/makes where they used the same chip. If the datasheet can be found I can then understand why it was chosen and then look for possible substitutes. Knowing what it does and looking at the rest of the circuit it will be clear what the motor wants to work properly and it is possible to design a completely new circuit to do the same
Back to the IC as it is the electronic heart. A couple of possibilities - while Veglia Borletti may have chosen it specifically for this speedo, it's also possible that in this particular time period - mid 80s - they had other speedos for other models/makes where they used the same chip. If the datasheet can be found I can then understand why it was chosen and then look for possible substitutes. Knowing what it does and looking at the rest of the circuit it will be clear what the motor wants to work properly and it is possible to design a completely new circuit to do the same