93 244 Speedo malfunction/abs lights

[nullspacebasis]

Hello,

I’ve recently run into this dirty electrical gremlin after getting a jump start and driving a bit - the ABS light on my 1993 240 comes on after reaching 10mph, and the speedometer itself shows an incorrect reading, sometimes bouncing.

Things I’ve tried:
- Replacing rear diff ABS/speed sensor with new Bosch part
- Swapping different speedometer K39200 into my cluster, original speedo K40168
- Reflowing solder on my original cluster’s speedo
- Retensioning, then later replacing, the connectors on the 3-pin L plug by splicing in newer ones from a 740
- Flowing solder on the 3-pin card edge connector on the speedometer for tighter contact with the plug
- Checking the ABS module fuse under passenger side carpet (fuse was good)
- Testing with a 91 cluster, K1xxxx (SRS light was on, speedometer motion was smooth albeit high reading)
[/list]

The odometer seems to have stopped as well. Anyone have any ideas? The wiring at the rear diff seems to be good, and I’ve checked the sensor signal with a multimeter on AC volts - the number increased smoothly from 0 at a standstill to somewhere around 4 volts at ~40mph. The current k4 speedometer won’t go above 20. I’m beginning to suspect I may need a remanufactured, known working ABS cluster.

At this point, I’m going nuts!