It was my own doing that caused the RPM guage to stop working on my car. Just not sure "which of the doings" it was, so I would welcome some guidance in trying to bring it back to life.
Last week I felt artistic and decided to pull the instrument panel on my 1987 300SE (126 ,M103) so that I could renew the Dash light Dimmer-hopefully improving the quality of it's light, while at the same time bringing back the bright orange color to the instrument needles that had turned pale yellow with time.
All went well and while waiting for these coats of enamel paint to dry - I decided to rinse the engine bay. Carefully and Gently....
I dried the engine real quick and it fired up immediately and has been preforming well these last several days. The instrument panel went back in without a hitch, after replacing some bulbs and rebuilding the Dimmer - Which in all fairness did not really need rebuilding. Heck, you never know that until you tear it down and open it up.
All the guages work now except the Tach so I know the fuse is good and everything is connected as should be (I believe) in back of the instrument panel. That makes me think I should look elsewhere and look into possible water damage. I was reading through the archives and the CD manual without success, trying to learn what governs the Tach on the M103 ? Is it a relay ? a sensor ? Where might it be located. TIA