I just installed a 140mph cluster in my 91' RS, and it works great, however, i now get a shift light, which is kind of annoying. Is that signaled by the computer or is that in the tachometer itself? Another thing i noted, a Oil Level light, any idea why that is there, yet these cars have no oil level sensors?

 

When the shift light turns on, do you notice if the torque converter locks simultaneously? The same ECM output is used for both functions, depending upon the transmission in the vehicle. Manual trans cars get a light bulb and no TCC relay, while auto trans cars get a relay and no light bulb in the cluster.

As long as the torque converter is working correctly, just remove the bulb.