I have an issue with my CEL and Fault display (94 NAS with 14CUX). I bought my truck last year and have had ongoing issues with the CEL coming on. The fault display has never worked. I have gone through much of the wiring and even replaced the warning lamp cluster, replaced the engine warning check light unit behind the dash (AMR 2041), bought a second hand fault display that I was told worked in its last application and tested the wiring from the ECU to the fault display. I have 12 volts at the brown/orange wire to the fault display unit and a good ground at the black/slate wire. No voltage readings at the pink and brown/pink wires but the CEL is on. I have cleared the CEL by unplugging the 14CUX control unit but the CEL comes right back on again when starting the truck the next time so I know something is up. Does anyone have any suggestions? Thanks in advance, really stuck with this one. Truck runs well but I would like to figure out what the cause is.