Hi I'm new to the forum and I have sum questions..

[396man]

Ok hopefully some one can help me figure my tachometer problems. I have a 1969 Chevy CST 20 with 396 and a factory tach. I just recently bought the truck and the tach only works "occasionally". I checked the wiring harness and all the connections are good. I cleaned where the brown wire goes on the coil and everything is clean and good. Sometimes I start the truck up and tach is working perfect and then driving down the road is starts reading incorrectly and quits. Any advice would be helpful.