Speedometer Troubleshooting

[NOLB]

I have been trying to figure out how to go about troubleshooting my speedometer unit. I don't have speedo or ODO. This is all of the information I have so far, and I would appreciate any input I can get.
I apologize in advance if this has already been discussed. I have tried my best to look for a thread or how to, I hope I do not cause a huge repeat.

I found two wires coming out of my diff's speed sensor, one is brown and one is brown with a red stripe. In the cluster I found two pins at the speedo that made continuity with the brown wire and one pin that made continuity with the brown/red-stripe wire. I tried to post pics but they are too big.
Is there a way I could use these pins to see if I am getting signal from the sender/sensor itself?
I would also like to exploit the exposed pins to see if the speedo is receiving power, as there is no light on. Is there anything I can expect to see? I guess I could go on

[NOLB]

Update: I have 12V from the top two pins.

[XLR8]

Update: I have 12V from the top two pins.

so as far as i can understand your speedo is not working ?
did you try to remove the speed sensor in your diff , i had one in there that was broken ,
you can have problems with a bad ground in your cluster try to add contact spray on your plugs that connect with the cluster

grtz hope it helps

[dlduke]

I see that this is an old post but people are still viewing it so: The odometers are notorious for having certain drive gears deteriorate. You can buy replacement gears from "garagistic". It takes a bit of finesse to replace them but you can find DIYs if you need help. I'm not sure if replacing those gears will help the speedometer. My speedometer kind of works when it wants to. On the E30s, there are a couple of rechargeable batteries that go bad and corrode the circuit board. Those can be replaced if you know how to solder. I replaced three odometer gears on my BMW 528E two days ago buy haven't driven the car yet to verify that it will hold.

[dlduke]

Great news: the odometer "rebuild" worked on my 528. Works perfectly. My speedometer is working consistently as well. I think having it sit for six months in the driveway caused the speedometer to be unreliable for the first couple of days. (The reason it sat in the driveway for six months was that I couldn't get it started due to a bad On Board Computer relay. That was a hard one to figure out.)