I have had a few 96 & 97 psd's and currently have a 2001 E350 psd. Would like to have to install a tachometer from an extra dash cluster from a 97 psd. So wondering if it would be an intelligent idea to wire directly into the data link connector black / lt blue wire. This is the same wire that runs to the tachometer on the harness on the older psd's. As well is another wire that is red/ yellow (power) to the harness . Thankx, Ronjon