benzy53 wrote:Guess what happends today. After driving for about 100km my tacho suddenly decided to work again.
Everything is fine now. The question still remains why did it stop. I'll pull out the cluster and have a
good look if there is something hindering the movement of the needle. Other option is maybe the
the sensor generating the signal.
It is good that it is now working - for how long will it continue to work?
You should be able to move the tacho needle easily with the side of a toothpick pushing in the direction of rotation. When the toothpick is removed, the needle should spring back to the 0 position every time with no signs of binding.
If you have access to a signal generator for generating tones from 200 Hz to 40KHz, you should be able to simulate the sensor signal to the tachometer.
If the tacho takes signals from the distributor, the following may be of use:
With a 6 cylinder engine there will be 3 spark signals per revolution, therefore 3KHz should display 1000RPM, 15KHz should display 5000RPM.
I discounted the sensor as it would not be sending any signal to the tacho, and the tacho has no power, when the engine is turned off.
Life is a journey, with problems to solve, lessons to learn, but most of all, experiences to enjoy.
'83 W123 300D 325000km (Josephine) - sold.
'84 W123 300D replaced good OM617 912 with OM617 952 and enjoyed having good acceleration for the first time since first driving a 300D in 2002 - became engine and trans donor for 300CD Turbodiesel conversion. Now parted out.
'86 W124 300D sold (Wife's old car - sold )
'85 W123 300CD, 275 000km (Fatmobile) rebuilt turbodiesel from previous Fatmobile transplanted into 280CE
'99 W202 C250 Turbodiesel (my darling Wife's car - Sold)
'98 W202 C250 Turbodiesel (my car)