I don't know if this will help, useing my 83 300SD as reference, yes there is a male connector that corresponds with the female connector. I did a continuity check across the male pins (six pins) numbered 2,3,6,7,8,9. Pins 7 and 8 have continuity, and pin 2 has continuity to both 7 and 8. The other pins did not have continuity. My tach is fully functional, I recently picked up two tach amps at a local pick a part junk yard for spares, they only charged me $5.00 I did a quick swap in and out of the two spares, one worked, the other did not, Iam going to remove the potting material (silicon rubber) that holds the male pins in place from the non working amp to check how the pins are connected and see if I can repair it.