Rpm Gauge Stops Working ?

[lexus1995ls400owner]

Just purchased a 97 LS400 with 130,000 mile on it. Proceeded to flush transmission fluid, replace serpentine belt, and attempted to flush the power steering fluid (couldn't get the return hose off the resevoir). After doing this, my RPM gauge stopped working ??? All the other gauges works fine though. Car runs fine and ODBII scanner shows no anomaly. Scanner show the RPM correctly, yet the instrument panel RPM gauge is stuck at zero. Any ideas as to what I might have done wrong ? Also reset the system (ie disconnect the battery and reconnect) but did not help.

[LA1]

With my wife's 92 the tachometer would work intermittently or react very slowly, sometimes sticking. Per the advise of someone here, I opened the gauge cluster and pulled the base of the rpm needle out until it made a slight pop; then I moved it up (clockwise) until it made a slight pop; then I moved it back to zero and let go; then I moved the needle up a little and dropped it and it went back to zero; reinstalled the gauge cluster and my tachometer worked again.

Hopefully this helps, but try it at your own risk!

[killerFatty]

Is it hot out? If so it might be the little bit of grease on the back of the needle heating up and sticking. Try smacking the top of your dash right over the Tach with some firm pressure. You may want to also give it some throttle to raise the RPM's will you try this so the gauge has more pressure pushing it up. If it pops to life than that might be the culprit.

[lexus1995ls400owner]

Thanks for the tip. I've researched the problem, but it seems most of the problem with the instrument panel were with the 90-94 LS400. Didn't see much with the 95-97 series. I've hit the instrument panel gently without success. I'm afraid to bang it harder since it might damage the more important speedometer. The tachometer did come back to life after a long trip yesterday, but is dead again this morning. It's definitely an intermittent problem. Revving the engine up to put pressure on the needle is a very good idea and I'll try it tomorrow. At least it sounds like I didn't break anything, rather the previous owner didn't say anything about it when I purchased the car. Weather here is very hot (90F) and I purchased the car when the weather was much cooler.