I'm trying to diagnose a dead speedometer problem on my 93 240.
ABS system work fine so I'm wondering if it unitizes the rear axle Speedo sensor pickup?

If so, wouldn't the ABS system show a fault if this sensor or wiring were bad?

I have replaced the instrument cluster and still no Speedo but ABS has always worked properly.

Yes, the speedometer sender in the rear axle doubles as the third channel (LF, RF, R) sensor for the ABS system.
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'63 PV544 rat rod, '93 Classic #1141 245 +t

So would this mean that no problems with ABS would eliminate a bad sensor or wiring?

Problem would then have to be in the Speedo?

Speedo went out intermittently and not all at once.

Did the speedo all of a sudden just quit. That's what mine did. I checked the guages and everything and found it was the sensor. It is in the diffirental cover. The manual says you may have to take off the link bar that goes from side to side. But, if you jack up the car and put it on jack stand that will allow the axle to droop you can get to it alot easier. It takes an allen wrench to take it out. It has a connector on it but it is safty wired together. I called the dealer and they wanted over $100.00 for it. I got it from a pull-a-part yard for $5.00. I just pulled out the sensor and cut the wires. It took me longer to find the right one than it did to take it out. If you have ABS just look for a car with ABS and your year or close to it. I think there are two different types. Feel free to email me directly if you have anymore questions.
Barry
bjersr@bellsouth.net

PS. I have a 740 and I just noticed you have a 200 series. I don't know if the are similar.

Thanks for the reply Barry.

The speedo went out intermittently over about six months.

I was thinking that since no problems with ABS the sensor and wiring MUST be good.

I have replaced the speedo cluster with another and still not working.
However, I can not be certain the new e-Bay speedo unit is good