I am confused by your reply. According
to the 123 cd-rom, the 1984 and 1985 diesels
don't get the tach signal from the diagnostic plug, but rather from a speed sensor near the flywheel. I have seen the diagnostic plug mounted tach sending unit on pre 1984 diesels
but the 1984 and 1985 diesels just have a plastic cover. Since the replacement engine is from a 1983, it doesn't have the flywheel mounted speed sensor. Do you think that if I were to put a tach sending unit in the diagnostic plug, it would provide the necessary signal to my tach. It is too expensive a part to buy for nothing. Your help in this matter is greatly appreciated as I hate to have gages and indicator lights that do not work.
Bosch certified DFI Tech
20 years experience
MBCA Member, Southern Stars