tachometer and cruise control connection?
 

Hello all:

Tach is dead on 1983 300SD -- cruise control will accelerate but not control speed are these two issues connected. Have 560 SL but LOVE my diesel!!

Thanks:D

I have noticed the same thing on my 300TD. When the cruise isn't working neither is the tach. There is a relay behind the passenger side, side kick panel. I have re-soldered a spare relay for this location but have not put it in yet. Maybe someone a little more familiar with the circuitry will speak up.

Cruise and tach tied together
 

Thanks for the info. How can we put our hands on a the schematics? I also have problems with the aux fan never engaging. Clutch 4.5 ohms -- I suspect ok. Measured >1 Vdc while engine is >80C. 70MPH will generate >100C heat after 1 or 2 mins.

Any ideas?

jeff

Can you take yours apart and photo the circuit board and the other side ? Hopefully from the same distance... and put a mark on two sides 90 degrees from each other when you photo it...should be able to make a schematic from that... and careful reading of the markings on the resistors, etc....