I've gotten most things repaired on this ride but the speedo is still dead. The fuses aren't the problem and everything is plugged in...

So I'm basically at a loss where to start. I did remove the sensor in the rear diff (is that a VSS or for ABS?) and it looked fine but heck if I know. As I understand it's very basic and uses a magnet to sense what's going on. The lil wheel it "sees" inside the diff turned freely also.



Is there a way to test that piece on the diff if that's for the speedo?

Does anyone just think my speedo is dead? If so, can this be repaired easily after I do some tests?



Thanks!

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

Not quite sure on your car what the yr is? The older models use a speedo cable to drive the head unit and later models were electronic. The unit in the diff is for the ABS not speedo. Have you removed the instrument panel yet? Is very easy to do so. If you get it pulled you can see the speedo cable. If you disconnnect from the head and drive car you should be able to see cable turn. If it turns then the trouble is in the speedo head. Then you need to send to the shop. Here is a link to a shop that I used and they were very quick and fair priced! Good luck!

Smokie

http://www.speedometer.com/services.html

The SDL is a 1987 model, it has an electronic speedo. I searched on here and later found the VSS is on the back left side of the trans and still hooked up.

I'm thinking on getting a cheap used speedo from the local boneyard to see if it's in the speedo OR the wiring. Everything looks hooked up properly and securely under there.

Unless there is some fuse/relay I'm missing under the hood I'm out of options.

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

If all your guages are dead then fuse #5 is blown, remove it to make sure it's good. I spent two days trying to figure out why I had no guages and I checked the fuses. Didn't know it was bad till I used a test-light on all of them.

You could all try getting a speed sensor from the boneyard if the new used unit doesn't work either. If none of those, I'm at a loss as that's just about replacing anything associated with measuring speed.

Thanks
David

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2000 Honda Accord V6 137k miles

1972 300SEL 4.5 98k miles

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Fuel, oil pressure, and coolant temp work as well as the tach.

I guess I'll try the speedo first then the speed sensor.

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

Time for an update.

Pulled the cluster and disassembled. The left turn signal bulb appeard to have somehow stuck on... this looks like it somehow hurt the circuit board the speedo is attached to.

I verified this as I picked up a used speedo from a 280SEL, plugged it in and it read MPH... tho' not correct obviously.

Glad it's not the VSS, that's a mighty spendy piece. I can deal with a speedo rebuild.

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]