the car an 83 300d t. tach was malfunctioning. did the search on rubber bands/cigarette butts etc. but when i actually open the hood and looked around i discovered that the wire to the 'tach' cylinder on the inside left fender was not attached to the engine. continued the search and found only the following cryptic reference "In mercedes a connection to the oil pump drive is used" (to power the tach?). my question where does the tach lead attach to the engine? also the square crossection attachment to engine end is covered in some type of epoxy. my epoxy has been somewhat abraided revealing the copper windings. second question. do i have to replace this wire given that i can see the windings? thank you.