speedometer problems on 97 GSX

[Plague23]

What I need to know is how the speedometer on a 97 GSX actually works. I mean how from point A (the water) turns into point B (the Speed in MPH)? The reason I want to know is that I have a problem with my speedometer and I was told that it was my speed sensor. I replaced it and nothing happened, and I tested the wiring which was good from the sensor. so I need a break down of the speedometer as I mentioned before, that the manual fails to describe. Then maybe I could get a better idea of what might be my problem and then I could fix it or sell back the sensor I got. If anyone could help it would be greatly appreciated.
PLAGUE23

 

[kustomkarl]

Here is some info on the spedo in a nut shell.
For the Speedo on the rear of the boat is a sender that uses a little wheel with 3 wires. 2 are for the the speed, and 1 is for temp. if your boat is equiped with the temp. quage. Using a multi meter attached to 2 of the wires, and spin the wheel you seed read restiance depending on how fast you spin the little wheel. Then check contunity on the wires to the guage. If it isn't reading it might be a broken wire. If it sends a signal to the guage, the guage is bad.

Karl

 

[Plague23]

Here is some info on the spedo in a nut shell.
For the Speedo on the rear of the boat is a sender that uses a little wheel with 3 wires. 2 are for the the speed, and 1 is for temp. if your boat is equiped with the temp. quage. Using a multi meter attached to 2 of the wires, and spin the wheel you seed read restiance depending on how fast you spin the little wheel. Then check contunity on the wires to the guage. If it isn't reading it might be a broken wire. If it sends a signal to the guage, the guage is bad.

Karl

so your saying that it reads the sensor by resistance, is that why the manual says to have the start timer on? also why does the manual say look for a voltage difference? I get resistance difference when it spins but i dont get a voltage reading at all. also the wiring is good from the computer to the sensor, then what else can i try to test to figure out this problem?

 

[kustomkarl]

My post is self explanatory. The 12 volts on the purple wire and the black wire to the guage is what gives the reading. The real reading is done in resistance. If it isn't giving resistance the guage is bad. There is no test for the guage direct.

I hope this helps you out.

Karl