I'm currently working on a mad scientist project to get a '93 J30 instrument cluster into an '85 Sentra coupe with a CA18DE from an '88 Bluebird. I have all the instrument lights, gauges, and tach working.
The only thing left is to get the speedometer working but I am unsure of all the components associated with the J30 speed sensor system. I've read on forums there are two speedo cables but my local junkyard is telling me a different story. Can anyone tell me what components are used in the '93 J30 speedometer system. I found a wrecked J30 locally so getting parts will be easy.
'93 J30 Speedometer Components
first, i can get you a picture of the wiring diagram if you need it.
basically youve got 5 speedo related connections. unfortunately wire colors will do you no good because you arent using the j30 harnesses (i assume).
1) power from ignition, same as for other gauges2) + from speed sensor (located on transmission)3) - from speed sensor4) a wire that sends the speed signal to the AT control unit5) another wire that sends speed signal to ECU
so basically, all you need to do is to get the sensor from the J30 or use another one and calibrate it with a resistor. (the J30 one varies from 0 to 5 V)
the speed sensor input on the back of the instrument cluster:
look for the middle connection port: it has 8 terminals total.
the two terminals on the bottom left of this port are the ones you need. (viewing cluster from back)
basically youve got 5 speedo related connections. unfortunately wire colors will do you no good because you arent using the j30 harnesses (i assume).
1) power from ignition, same as for other gauges2) + from speed sensor (located on transmission)3) - from speed sensor4) a wire that sends the speed signal to the AT control unit5) another wire that sends speed signal to ECU
so basically, all you need to do is to get the sensor from the J30 or use another one and calibrate it with a resistor. (the J30 one varies from 0 to 5 V)
the speed sensor input on the back of the instrument cluster:
look for the middle connection port: it has 8 terminals total.
the two terminals on the bottom left of this port are the ones you need. (viewing cluster from back)
So really all I need is power and the two connections from a speed sensor. I may also need output to ECU but it's not a problem. If I can't get a J30 sensor I'll go with a universal for aftermarket speedo. If you could get me a picture that would be great. My email is [email protected]. Thanks for the reply.
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Q45tech
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- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
The transmission mounted speed sensor [generator] generates a variable frequency which is sent to speedometer which contains a D/A convertor which translates the driveshaft rpm into a 0-5 volt signal for the speedo volt meter and steering, tcu, and ecus.
The [replaceable] plastic gear on the speed sensor sets the ratio vs the differential gear and tire diameter so that the speedo volt meter reads correctly.............x driveshaft rpm equals y volts.
As I remember you can get Nissan speedo sensor gears in 4-5% increments for 3.54, 3.69, 3.90, 4.08 diffs plus 2.8, 3.31 and others.
The [replaceable] plastic gear on the speed sensor sets the ratio vs the differential gear and tire diameter so that the speedo volt meter reads correctly.............x driveshaft rpm equals y volts.
As I remember you can get Nissan speedo sensor gears in 4-5% increments for 3.54, 3.69, 3.90, 4.08 diffs plus 2.8, 3.31 and others.
Wow, great info. I'll have to find out the ratio for the JDM 5spd transmission I have and work from there. The other option is to use an aftermarket calibration unit like this:
http://128.83.80.200/taco/speedo.html
http://128.83.80.200/taco/speedo.html
Man, how did you find me here Average?
Anyway, I pickup up a speed sensor/pinion assembly from an Infinity G20 the other day. It was identical to my pinion assembly except for the cable vs. sensor. I got it installed and wired to the speedometer with partial success.
When I turn on the ignition, the speedo jumps to 17mph and hold there rock steady until I move. Any idea what's causing this? Would it work to just pull the needle and reset it so it's at zero when not moving?
Finally, the speed is really off. The gears on the old and new pinions appear the same. Should I pull the pinion gear off the old assembly and put it on the new one?
Anyway, I pickup up a speed sensor/pinion assembly from an Infinity G20 the other day. It was identical to my pinion assembly except for the cable vs. sensor. I got it installed and wired to the speedometer with partial success.
When I turn on the ignition, the speedo jumps to 17mph and hold there rock steady until I move. Any idea what's causing this? Would it work to just pull the needle and reset it so it's at zero when not moving?
Finally, the speed is really off. The gears on the old and new pinions appear the same. Should I pull the pinion gear off the old assembly and put it on the new one?