SORRY ABOUT NOT POSTING WHAT AUTOMOBILE THE TACH QUIT WORKING ON. IT IS A 1995 MERCEDES 300E DIESEL. I WOULD LIKE TO KNOW HOW TO TROUBLESHOOT IF THE PROBLEM IS WITH THE WIRING OR THE SENSOR ITSELF? SOMETIMES THE TACH WILL WORK IF THE ENGINE IS RIVING UP ABOUT 2500-3000 RPM THEN IMMEDIATELY IT DROPS BACK TO ZERO. I HAVE CHECKED THE FUSES AND FOUND NO TROUBLE WITH THEM. IN FACT I DO NOT THINK THE TACH IS FUSED, IF SO, I CANNOT FIND IT.
THANKS!
LARRY L L