I bought a replacement LCD unit for the outside temperature display for my '87 300D. The old display was turning black. However, the new display has 5 inline pins labeled 1,2,3,4,5 where the old one has 4 pins (square 2 + 2) labeled 1,2,3,4. I figured the 5th pin on the new display was not needed, since the new part was listed as a replacement part for the original in the parts manual. After buying the new inline connector at the dealer (about $2), I wired 1-1, 2-2, 3-3, and 4-4 and all that comes on is the light, no temp indication (blank).

Any ideas?


'87 300D (178km)
'01 CLK 430 (21km)