Electronic Speedometer

[Jan Venter]

Hi i need help installing a aftermarket speedo. The Lexus gearbox i have has a gear with 3 wires sticking from it. This is on the RH side right at the back close to the rubber doughnut. Can this be connected directly to the speedo or do you need to go through a box of some kind to translate the signal. Please help. Jan Venter

 

[George_R]

No special box is needed. The 3 wire part is a Hall effect sensor with open drain/open collector output. The wires are +12, ground and signal output.

Most aftermarket speedo's don't natively support open drain output so you should run 1kOhm resistor between positive power and output wires of the sensor.