Rev Counter Not Working

stericker · October 15, 2013

I have just noticed that the Rev Counter on my '99 LS400 is not working. I tend not to look at it

very often so it might have packed up some time ago. Any thoughts on how to get it going again

and should I be concerned that it is not working ? A couple of weeks ago I disconnected the

Battery - could that be a reason ? Grateful in advance for your input.

Malc · October 15, 2013

Mine sometimes just sticks for a few hundred yards then frees itself ..... depends on the weather methinks !!

Malc

steve2006 · October 15, 2013

My speedometer occasional sticks and a sharp thump on the top of the dash usually brings it back in action so I would try that first.

This fault tended to affect the earlier models but the needles look the same throughout the model years so later models may now be affected by the same problem.

If it does work with the shock treatment there is a proceedure to clean off the excess lubricant on the spindles which causes them to stick.

stericker · October 16, 2013

Many thanks Malc and Steve for your input (as always !!)

A thump (and not a very hard one) on top of the dashboard brought the rev counter back to life immediately.

Malc · October 16, 2013

It's good sometimes to have low tec capabilities ...... wonder what Lexus might have charged to remedy the " challenge "

Malc

Bluesman · October 16, 2013

It's good sometimes to have low tec capabilities ...... wonder what Lexus might have charged to remedy the " challenge "

Malc

I think it would depend on the size of the thump needed and of course how many of those thumps are needed.

Bluesbreaker · October 18, 2013

I had a work colleague once; who used to 'stick' quite frequently, I also found the old tried and tested remedy,mentioned above,was best applied around this guys backside,-usually wearing a suitably heavy boot, -it never failed to work, a practice, unfortunately, these days,much frowned on-I cannot imagine why though.....

MacCymru · April 9, 2016

I just heeded the advice offered & it actually worked. I realise this is a thread 3 years old. But good advice is priceless. I gave it a simple tap on the dashboard with the palm of my hand..Magnifique! .

The-Acre · April 9, 2016

2 hours ago, MacCymru said:

I just heeded the advice offered & it actually worked. I realise this is a thread 3 years old. But good advice is priceless. I gave it a simple tap on the dashboard with the palm of my hand..Magnifique! .

Nothing quite like the good old fashioned recipes!

Tulpen · April 10, 2016

Many years ago, I was an RAF Aircraft Maintenance Engineer. We were always taught that, because of the fine machining tolerances involved in aircraft manufacture and assembly, we were NEVER to use excessive force on anything. 'Fit it - don't force it!' was the mantra.

One day, I was trying to fit a bearing into a housing, but it just wouldn't go. Eventually, I went to find the Chief Technician who, after inspecting the problem, went off then came back with a large wooden mallet. He positioned the bearing and gave it a mighty whack.......it fitted perfectly.

'But, Chief,' says I, 'we were taught not to use excessive force'.

'That wasn't excessive force', he said, 'that was a therapeutic tap.......and when you've been engineering as long as I have, you'll know the difference'.

So, if all else fails, try a 'therapeutic tap' :)

mrdoofa · April 10, 2016

As others have said a good thump on top of the dash can get it going again.

malcolmdc · June 24, 2016

On ‎10‎/‎15‎/‎2013 at 11:05 AM, steve2006 said:

My speedometer occasional sticks and a sharp thump on the top of the dash usually brings it back in action so I would try that first.

This fault tended to affect the earlier models but the needles look the same throughout the model years so later models may now be affected by the same problem.

If it does work with the shock treatment there is a proceedure to clean off the excess lubricant on the spindles which causes them to stick.

I picked up on the middle paragraph here - my 1991 LS400 rev counter is reluctant to register; nothing on tickover, wavers up to about 1500 only during driving! Haven't found anyone with a suggestion - was it a known problem?

Malc · June 24, 2016

.... just an update on mine since Oct 2013 ............. it's been fine since

Malc

malcolmdc · June 27, 2016

I am clearly only a beginner with the THUMP technique - One good thump and its finished it off completely, with needle now right at the bottom, motionless! Are rev counters repairable, or am I advised to get a salvage replacement, or is an Auto-electrician likely to be any help? Steve, you mention a "procedure", is it a DIY or a money job? A dead rc is not the end of the world but the rest of the beast is so good its a bit of a shame . . .

ambermarine · June 27, 2016

Malcolm

The rev counter works electronically from an impulse generated in the engine it is converted to the mechanical readout (needle) within the combination meter and the pyhsics although simple are very difficult to get into let alone fix.

Even replacing the combination meter is quite onerous and as you say it is not that important on a automatic transmission.

runsgrateasanut · May 8, 2017

Just back (2 am)from 600 mile drive from France (yawn) and my LS behaved admirably.. Always good to select a return on Sunday when their are no Lorries allowed on the road other than refrigerated. Road to ourselves and good cruising speed.

Only surprised when parked up at Calais after the now usual double seach by the boys with the weapons slung on their shoulder, that the Rev counter was not working. It certainly was, for all the journey whenever I glanced at the speed. Anyway it started working again once in Dover and seems to now be OK. Must have got a fear of Water!

Malc · May 8, 2017

I raised another thread on this a little while ago ( this year ) and mine still doesn't work .............. properly.

There is no known simple fix, just accept it or change the whole dash for a replacement one ( that fully works ).

It's not an MOT issue, a non working rev counter, it's just irritating that after all these years it's never showing the correct revs ( I guess ) if it shows any at all !

So frustrating

Malc

runsgrateasanut · May 9, 2017

Glad its not an MOT issue but neverhteless there is nothing more irritating than something not working which you are constantly looking at! Malc you have my sympathy. I'd rather have been given a dent somewhere by a trolley which I'd barely ever notice than have something right before me not working properly. As you say, so frustrating! Won't be using the thump method if it should refuse to budge again as I imagine such a sensitive piece of equipment does not really respond to bullying.

Malc · May 9, 2017

I remember the days when it was a great thing to go buy a rev counter to fix up alongside the dash ....... boy racers did that back in the 60's

Malc

runsgrateasanut · July 24, 2017

On 08/05/2017 at 11:17 AM, runsgrateasanut said:

Just back (2 am)from 600 mile drive from France (yawn) and my LS behaved admirably.. Always good to select a return on Sunday when their are no Lorries allowed on the road other than refrigerated. Road to ourselves and good cruising speed.

Only surprised when parked up at Calais after the now usual double seach by the boys with the weapons slung on their shoulder, that the Rev counter was not working. It certainly was, for all the journey whenever I glanced at the speed. Anyway it started working again once in Dover and seems to now be OK. Must have got a fear of Water!

Well blow me if after another 1200 mile successful trip to France returning on the 11.35 pm Ferry to Dover last night after with no rev counter issues, I noticed starting the Car on the Ferry the Rev counter needle wasn't moving. Selected 2nd gear as normally do in going up the ramp, but this time going down, and low and behold once off the Ferry it started working again for the160 miles journey home. Seemed to work perfectly.

Surely this must have something to do with electronic intereference, perhaps more so, at Ports?

Malc · July 24, 2017

you can see my other post here ............ mine's working fine right now, the very hot weather possibly leaked a little of the stuff that solders these joints or whatever AND it's back to the day she was born, in October 1995

see....... " no hands or actual manual interference " these cars sometimes cure themselves of their misdemeanours

Malc

Roberts_1409 · May 18, 2019

I know this is an old post but it helped me out big time. My 98 LS400 has been off the road for a long time, and the Rev counter gave up on a test drive last week.

A good thump and she’s back to life again! Well worth a shot! Thanks guys

mrdoofa · May 18, 2019

5 hours ago, Roberts_1409 said:

I know this is an old post but it helped me out big time. My 98 LS400 has been off the road for a long time, and the Rev counter gave up on a test drive last week.

A good thump and she’s back to life again! Well worth a shot! Thanks guys

If in doubt give it a clout!!!

runsgrateasanut · May 20, 2019

Same thing at Calais a week ago (must be heat related as had driven 420 miles) but also my Speedometer stopped working briefly during the trip to France. Started again after about two miles but a bit more worrying as I recall it not working just before the last MOT. Got until August to worry about it failing again - just at the wrong time! Not going to dash the dash, however. Resisting that.

runsgrateasanut · June 3, 2019

I hope "Rick" of another forum won't mind me reproducing something he wrote which I eventually trawled down too, on the subject.

At your own risk you follow the advice here but with the sticky weather having arrived and hopefully staying it seems that the answer to the problem has been found, or perhaps confirmed. Quote:

For those of you who would like to fix the sticking speedometer and Tach needles yourselves, at no cost, the solution is simple, but takes some careful disassembly of the gage cluster to remove the sticking gage. First, remove the cluster. (http://www.lexls.com/tutorials/elect...ntcluster.html) Then disassemble the cluster (http://www.lexusownersclub.com/Lexus...rd_Removal.pdf) by removing the 4 screws from the power supply board and folding it back, then the screws holding the main board to the frame. Remove the ribbon cables by carefully prying up evenly on the wedge lock, and the other connectors by lifting straight up.
Once the gage is removed you can access the needle limit stop arm from the back side. The sticking is the result of lube getting on the limit stop arm and causing a slight vacuum (much like denture adhesive) when the needle disk contacts it. This vacuum has to be overcome before the needle will release from the limit stop. There is no need for any lubrication at this location, and it must be removed.

Take a Q tip and remove most of the cotton from one end. It will fit nicely alongside the limit stop arm. Make sure the needle is pointing toward 50mph and not on the zero point. Insert the tip on the face side of the arm and once the tip reaches the end of the arm, rotate it gently to remove the lube. Then, even more gently, rotate the needle back toward the zero position until the limit stop on the disk contacts the Q tip and rotate the Q tip another turn while applying very gentle pressure on the back end of the needle arm. Rotate the needle away from the zero position and extract the Q tip and the sticking will be gone. Reassemble and grin widely, knowing that you saved yourself a couple hundred bucks. -Rick

Unquote. Thanks again Rick.

May give this a try sometime as both seems to stick most days now for a brief period