combiinstrument is crazy!

tach together again have a problem with my father's v8 which I would like to get baked!

so the speedometer of the bc and the tank indicator do not go most of the time then when you just don't strike jump se for short time and as fast as you were on you also go out again...

I'm totally at a loss.

I had the combin instrument soldered the soldering holes had the complete amatur board below including all the wiring trees and strenghts to look for nem cable break but found nothing...

I really need advice had the problem already someone!!

thanks for the help!

mfg alex