My '92 240sx is having a problem with the speedometer. It doesn't always turn on when
the car does. If I wait about 3 minutes, it will turn on. Sometimes turning off the car
then turning it back on again will make the speedometer show. Does anyone know what is
Well, I have never cracked the speedo open on my '90, but I have on other cars, and I
think all are pretty much the same. There is only a couple of places where it could be
"slipping". 1) At the transmission - this is where the cable screws into the
side of the trany, there is usually a little gear here that turns with the trans, thus
turning the cable, which determins the registered speed. This could be missing teeth or
broken, or just a bad connection. 2) At the dash - the same cable screws into the back of
the speedo. There are little "teeth" on the ends of the cable that lock into a
slot at their respective conections. These could be damaged. Unless it is
something in the speedo itself, I would bet it is a cable problem. Anyway, I don't claim to be an expert, but I would start by checking out the cable connections, then go from there.
Trevor, I am not sure how the trans is set up on a '92'. But I do know that on the 89
& 90 a speedometer sensor is used, not a cable. I have a 89 and experienced the same
problem that you are describing, it was the speedo sensor. This sensor is located on the
side of the trans, basically right below the passenger seat. The sensor is @ $60
from NISSAN if I remember correctly and isn't very difficult to change yourself. Just make
sure you drain the transmission before you do so. Any questions give me a holler.
Later and good luck,
Speed Sensor Check
The Speed Sensor is on the right hand side of the tranny just at the end where the drive shaft comes in.
To check it's operation, remove the sensor and measure the voltage (A.C.) across the 2- terminals. Spin the pinion quickly and you should get approx. 0.5V A.C.
Hope that helps,