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Discussion Starter #1
92 stealth rttt. Speedo hasn't worked since I bought the car. I've tried 3 different sensors on the tranny, the square key is there, the plastic gear that goes in the tranny is fine, no flat spots or broken teeth. I have 5.3 volts at my yellow wire that goes to the sensor. 11.5 at the black with white tracer. I've taken the cluster out and put it back in 4 or 5 times to make sure it's seated all the way. I am out of things to look at. Any advice? Thanks in advance gentleman.
 

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You checked the voltages at the sensor, did you check the ground?

I would tap into the 5v reference wire and see if it's making a signal. You should be able to unscrew it from the trans and turn it by hand to make a signal.
 
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Discussion Starter #3
Ground read a 0.0.... I'm not a wiring expert by any means. I'm assuming by turn it you mean the square key? So the black with white tracer is the constant and the yellow is what sends a signal to the cluster? Or does it go to the ecm then the cluster?

To add into this my cruise is not working. Nor does the ecs but the ecs is unplugged. Would that have anything to do with it? I read through the other 7 page thread and tried everything there.
 

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When testing grounds I like to use a test lamp... I want to have enough current flowing to light up bulb, so I know it has a good connection and is capable of carrying current. But at a minumum you should show full battery voltage when connected between the power and ground wires at the speed sensor connector.

The sensor should pull the 5v to ground as it turns... It should cycle between 5 and zero volts as it turns.
 
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Discussion Starter #5 (Edited)
I had the multimeter with the ground touching the battery ground terminal and the red on the yellow wire. I had a constant 5v with the key on and not spinning the sensor. Is that right?
 

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Replace your speedometer.

I've ran into this issue before. The first vr4 I bought the speedometer never worked mileage was stuck. I replaced the speed sensor, did nothing.

My current vr4, the speedometer didn't work. There is thread that shows you how to test the sensor. I actually made a device to test the speedometer sensor to know that it's working.

It went something like connecting it to a voltmeter and spinning the magnet if the voltage increased the sensor was good.

I replaced the whole speedometer with a known working one and that solved the problem. The Twin Turbos have something electronic that does bad inside the speedometer, I forgot which part goes bad but replacing the speedometer worked for me.
 

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So just swap the whole cluster?
Yup find a good working one that is, at or a little below your mileage and swap it out.

It's pretty easy to replace.

92VR4Widebody usually has good working speedometer from 3000gt vr4s. I would send him a PM. I got mine off of ebay.


Edit: Here is a link to a thread I created a long time ago when my speedometer wasn't working. The final solution was replacing the whole speedometer. That fixed the issue.
http://www.3si.org/forum/f35/odometer-speedometer-not-working-535722/
 
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Discussion Starter #9
After reading that I don't think the cluster is my issue. Everything works on my cluster except the speedo. My cruise also does not work.
 

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I hope your issue isn't the same as mine was. It ended up being the actual gear inside the tranny attached to the differential, It came off, I ended up installing an OBX diff that had the gear made into it and it fixed the issue.
pull the sensor out and get a light and look down into the tranny and see if the gear is engaging the gear on your sensor.

good luck man
 

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99% sure its your speedometer - Your speedometer can be replaced separately without the cluster.

That's the reason my doesn't work, Just been lazy about replacing it
 

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I bet its the speedo gear on the diff. Yours is most likely a metal casting in the diff housing. My 98 has a PLASTIC ring that has split and the speedo reads slow. Pull the whole speedometer gear cluster on the trans and look down the hole, check the condition of the diff gear.
 
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Discussion Starter #13
Speedo gear on the diff is good. Looks good, plastic gear on the sensor fits right, no slop. Correct me if I'm wrong but the speedo sensor sends signal to the ecm before it goes to the cluster right? So if my cruise doesn't work then the ecm probably isn't receiving the signal from the sensor. Need to check for the pulsating on the 5v wire next.
 

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I believe the RPM will work but the speedometer didn't work. The mileage never increased. The gas was registering too.

The problem was the speedometer was bad. Like I said I would install a good working speedometer, that will eliminate alot of the guessing.
 

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The speed sensor sends the signal directly to the ECM, speedo, and cruise control module. It sounds like either the sensor isnt working, or there is a wiring problem. Put the square key in the chuck of a drill, and hook up the speed sensor to the wiring and then use the drill to turn the sensor while the key is on and have someone watch the gauge. If the needle moves, then you know its the portion in the trans that isnt spinning the square key. If the needle doesnt move than you need to test the sensor itself. If the sensor tests ok then verify the wiring is good.
 

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The speed sensor sends the signal directly to the ECM, speedo, and cruise control module. It sounds like either the sensor isnt working, or there is a wiring problem. Put the square key in the chuck of a drill, and hook up the speed sensor to the wiring and then use the drill to turn the sensor while the key is on and have someone watch the gauge. If the needle moves, then you know its the portion in the trans that isnt spinning the square key. If the needle doesnt move than you need to test the sensor itself. If the sensor tests ok then verify the wiring is good.
What the hell you talking about...? We don't test things on this forum, we toss parts at it until something sticks... :lol:
 

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The speed sensor sends the signal directly to the ECM, speedo, and cruise control module. It sounds like either the sensor isnt working, or there is a wiring problem. Put the square key in the chuck of a drill, and hook up the speed sensor to the wiring and then use the drill to turn the sensor while the key is on and have someone watch the gauge. If the needle moves, then you know its the portion in the trans that isnt spinning the square key. If the needle doesnt move than you need to test the sensor itself. If the sensor tests ok then verify the wiring is good.
That's a pretty good test to do. This would have saved time when I done it.

I guess I took the harder path wiring up a resistor and using a multimeter LOL.
 

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That's a pretty good test to do. This would have saved time when I done it.

I guess I took the harder path wiring up a resistor and using a multimeter LOL.
Great starting point, and is a time saver when the usual suspects turn out to be the culprit. But I also maintain that it's best to have the ability to do further tests when the problem turns out to be non-typical.

I use a lab scope to test systems like this, but I recognize that it's not an option for most. When looking for digital signals without the luxury of a scope, I recommend an LED test lamp. I have one wired in series with a 1kOhm resistor that works very well for such tasks. It will give a nice visual of what's going on, but won't draw enough current to effect or hijack a low voltage signal. (I use the same lamp to check codes on 1st gens... MUCH nicer watching a lamp flash than trying to count needle swings.)

In a case like this, the obvious first step is to determine if you have a signal or not... While the cruise not working also is a possible symptom of no signal. there are plenty of other reasons the cruise may not work, and I'm not willing to hang my hat on that, and waste testing time on an assumption. If you do have a signal, then the obvious suspect would be the speedo head. Once the signal, power, and ground is verified at the speedo connector you could replace the speedo with confidence. If you don't have a signal, then you need to find out why... (which is where the real fun starts)
 
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