I've got a 1982 basic model and I've installed the SR5 cluster. I used the new pin-outs and everything is working except the tach. I've read through the threads and followed the instructions but without success. I know the gauges worked before. I've followed the back of the panel to the #14 screw for the tach, attached a wire there and then tried both the plugged end and the other wire as shown in some of the earlier photos. Any trouble shooting thoughts out there? Thanks.