francisluu

I was looking at this DIY and was curious if the unit would be functional (obviously only for the digital speedometer) if only the power and speedo signals were tapped instead of all of the other sensors?

I also didn't quite understand what this meant from the article — "OBC Tachometer connector: Not available separately from dealer, need to find a used part off a 993 tiptronic, Turbo, or 6-speed w/OBC option or use the connector off a 1990-1994 964 w/OBC option."
https://www.pelicanparts.com/techart...r_retrofit.htm

Endoman

I did this retro a few years ago and the digital speedometer is not very accurate. The plug for the OBC is quite different and difficult to find I managed to get one with the speedometer, it is used on some BMW's. I find the temp and miles to go on fuel the most useful (I ignore the mpg.) I presume it would work if only for speed. Can't see the point. The temp sensor loom should be present and can be tapped into at a connector block under the bonnet hinge (r/h on rhd). The other signal points are a bit trickier I made up a short loom with a socket for the original speedo plug, so no cutting or splicing there. The others need wires running to the ECU block as per article. The OBC speedo is very expensive from a dealer and there are differences depending on model so you need the right one for your car if you can find a used one, which will probably have a faulty display (can be fixed) unfortunately it's not plug and play but quite fun to do.