91 LS400 w/ broken Speedometer

[Decker91LS]

I just purchased my first Lexus ever, a 91 LS400. However, my speedometer is not working. It normally sticks around 40mph but on the highway yesterday it started to move around. I read a post that said that said it could be the speed sensor on the transmission tail shaft. I was wondering if there is anything else I should look at as the source of the problem? Everything else in the dash is working, tach, odometer, lights. Also, would this throw a CEL?

Thanks everybody...

 

[Lextreme II]

Get one from your local junk yard.

 

[ABDULLAH D AFGHAN]

I know this is an old thread but I was wondering if Heat or Temperature had anything to do with the Speedometer. Mine was not working and sometimes would work when id go over 50mph or over bumps or when i drove the car for a long time. Ever since i changed the thermostat and coolant though, it works everytime even right when i start the car. Is it just a coincidence?

 

[stevechumo]

I know this is an old thread but I was wondering if Heat or Temperature had anything to do with the Speedometer. Mine was not working and sometimes would work when id go over 50mph or over bumps or when i drove the car for a long time. Ever since i changed the thermostat and coolant though, it works everytime even right when i start the car. Is it just a coincidence?

Yep. The temperature and heat have everything to do with the entire cluster. The most common issue is the resistors on the board circuit go bad as they age, most likely due to the heat. The next issue is if the resistors are still ok, then the needles got heated up by the tiny lights inside them. This heat will make the needles get stuck around their bases. The other issue is the motors to turn the needles go bad as well. Get a good working from the junk yard will solve the problem. :bigok: