I am wondering if anyone can help.
I installed a trip computer (which a got in the breaks yard) in to my 1998
406 LX TD. I know my car wasn?t wired for the trip computer, well not for all the functions. My car was wired to display Radio & temperature (I had to add temp sensor to door mirror). For the other functions to work the trip computer needs a few other wires to receive the needed signals. I did some homework on this before hand and read the wiring diagrams in the Haynes book. As the wires only go to and from the instrument panel, I decided to do some DIY connecting the 4 wires plus 2 to new push button to substitute for push button on Wash/Wipe stalk). Temperature/ average MPH/ Journey length in miles all work okay, but my problem is fuel economy, MPG etc does not work. The trip computer does have a reading for the amount of fuel (in mileage) left in the tank, but it drops this after about 10 minutes into a journey. My question is; should I give up now as my car needs more than a trip computer for all functions to work i.e. a higher spec instrument panel or has anyone seen these problems before with factory fitted trip computers?