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Junior Member
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Discussion Starter #1
I have a 1994 KW W900 and I'm trying to get my speedometer to work. Anybody have a wiring diagram? Is it wired thru the ECM or directly from a speed sensor on the trans?
 

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This may help some but that year it would not be ECM driven.If you look the VSS will have a single sensor with four wires or two sensors with two wires each.
 

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Discussion Starter #3
Here's a pic of the back of my trans. It looks like there could be 3 sensors but at the very least 2. One single sensor at the tailhousing near the spud shaft and u joint and another one(or two?) that come from the black box at the bottom.



I am getting power at the speedometer and when I turn the key on without starting the truck the speedometer does indeed jump slightly as it is supposed to.

BTW thanks for that link. I was able to find an in-depth guide but now I need to figure out exactly which model of speedometer I have before I can proceed. No markings or labels on the back as best I can tell.
 

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Discussion Starter #4
Here are a few shots of the speedometer. Maybe somebody can ID it? I'm guessing it's the 900 series. There is an old and long faded sticker that can't be read.





 

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Did you try to open the link I posted as home page?It has what you need to look at.With two sensors on your trans tells us that one is for the ecm and the other is for the speedometer.One way to check the head is look and see if the tachometer don't have a plug in wiring like the speedo.It should and you can plug the tach wiring into the speedo and start the engine.The speedo should now move some wht like the tach if its good.Also some of the sensors have the same plug in on them and you can plug one into the other at the trans and see if this makes the speedo work.The link I posted shows how to ohm out the sensor.
 

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Discussion Starter #6
Did the OHM test at the dash and not getting anything. Did an OHM test at the sensor itself and getting resistance.

There is just one sensor and the wires plug into that box in my photos then 4 wires come from that box and travel up towards the front of the truck.

Any guess what that square box is? It's just bolted to the trans on an angle bracket. I've tried asking KW but they're pretty mum on the subject.
 

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That is a speedo buffer and was installed on cats with PEEC controls.I cant remember much more than that.Its been 15 years since I worked on one.
 

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Discussion Starter #8
I appreciate it.

Bought a new sender just so I can start from there then going to dive into

the wiring a little deeper
 

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Longshot,

Cs641, did you figure out the problem? I have a 95 w9 with 3406c(peec) converted to mechanical and I'm having the same issue
 
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