After some local resurfacing on roads my brava 100 sx speedo has become erratic mostly reading 0 .please i am confident at working on the car but don't know where to start

Start with the simplest first: Speedo cable interuption somwhere?

Check the connections at the speedometer end, and gearbox end. Where they join them, have they been dislodged?

Good luck!

Thanks is it easy to get to the speedo connections

Just a thought

I have a 99CV early Brava (Brasilian spec engine). I had various gauges that were failed when I got the car. I pulled the dash and found that they were all caused due to bad / dry solder joints.

Although my speedo was the one working gauge, there were signs that a previous owner had already remade solder joints behind the speedo.

For me just running an iron around fixed everything. The speedo is electronic pulse driven so I would say that vibrations have lead to electronic failure / bad connections behind the dash panel.

I also had the same thing on all the windows switches. None of the lights worked but a surface mount resistor on the feed to the LED was the cause in each case.

Nice cheap easy fix.