I see this has been covered a lot but my issue is a bit different, or im just flat seeing the simple. and yes I searched lol, 2000 civic obd2b d16y8 with jumper harness to obd1, My tach is not working correct. Ive read post all day and did what everyone seems to say to fix it..so far Ive ran a new wire from the distributor icm spare terminal to the lone blue wire on the driver side shock tower.with no help in fixing it.when I start the car the tach jumps once or twice the just stops working, Ive tried 2 different ecu ( P28 AND PO6 )and 2 different gauge clusters with the same problem. keep in mind I got the jumper harness from some kid just bc he didnt need it so its probably an ebay jumper. so could the jumper be the problem ? if so when I get a good jumper should I unhook the blue wire from the distributor to the shock tower.