Rod Shellshear

Hi, I have had a 1998 Lexus Ls400 now for 15 years. I had the same problem with speedo and tacho working intermittently around five years ago. The fault is not due to oil or grease or the cluster ECU. When the cluster is removed and gauges separated from the circuit board you will see that both speedo and tacho gauges have four pins each which engage sockets on the ECU when the unit is assembled. The sockets are individually pressed into the PC board and become loose over time causing a bad connection. There is a simple repair which I did all those years ago with no further problems. The solution is to remove each socket from the PC board and apply MG Carbon Conductive Assembly Paste (do a search to find a supplier) and refit each socket turned 180 degrees from its original position. Apply a little paste to each pin of the speedo and tacho and reassemble. I have heard the fuel and temperature gauges can also give the same problem so it is a good idea to do follow the same procedure for these at the same time. Trust this helps, Rod. (Australia)