My tachometer in my 1982 300 TDT is not working. I have replaced the RPM sensor, but this does not seem to be the problem. I have two of them now and it works pretty much the same with the guaranteed good junkyard one and also the brand new VDO one.
Mostly it doesn't work. Sometimes if I pull and yank around the wire harness from the sensor near the crankshaft balance pulley on the front of the engine, the tach will work properly for a short time.
But mostly it just sits dead. But when I tap the horn button on the steering wheel, the tach jumps to life for a split second. Repeated very quick taps get it to hover around 1000 rpms. The horn and the tach are on the same fuse.
Any ideas?
Thanks.
Paul Fretheim