my speedomner only works when it wants to and some times it just jumps around 4 a few secs then goes to normal or just sits at 0 4 a few miles then stats working or if i hit a bump hard it will stop working or stop i know these are eletrical where should i look 4 a bad conection or a losse ground or wut the dash lites sometimes goes off too and i hit the dash and theyll light right back but dose any1 know wut it could be a pervious owner of the car set it up where u have to flash the high beams to start the car maby where they ran the wiers or sumting i dk they did it relly clean i dont see the wiers that they used under the dash.

thx mike