VDO electronic speedometer issue

[travisr1988]

I just installed a VDO electronic of speedometer and wired it up per instructions, and tried to calibrate it but the needle wanders and doesn't show the correct speed. I used a Dakota digital inductive sensor for GM transmissions after confirming it was compatible with my transmission. Had no issues with the install, wires from the sensor go to pi s 7 & 8, power to pin 4 and ground at pin 3. Simple enough, verifies good connections bit still it wanders. The instructions didn't specify where to ground the gauge so I used the same ground as all the other gauges which all work great, could it be this one needs a better ground? Or could my speedometer gears be messed up? What am I missing here?

[VileZambonie]

I used a Dakota digital inductive sensor for GM transmissions after confirming it was compatible with my transmission

Did you confirm it's compatibility with the speedo?

[travisr1988]

When I talked to the speedo manufacturer before purchasing they said any inductive sender will work and has had customers use the same set up without issues. Anyway, today I ran a bigger power wire, and a bigger ground to the fender ground, checked the sensor wiring and still it bounces and wanders and I recalibrated it using the family car and marking exactly 1 mile, but even when it stops wandering it's way off. I'm beginning to think the sender or the speedo is defective. I'll test the sender tomorrow after work, hopefully it's the sender as it's cheaper than the speedo and with all that's going on I really don't have money to spend on the truck right now.