'85 Mondial Cab -- Speedo needle jumping

I just noticed the needle bouncing on the electronic speedo over the weekend. It has never done this in the past 6 years I've owned the car. Is there a transducer/sensor somewhere that I can check out for contamination or a frayed signal wire -- or something?

Thanks,

michael

 

Yes-- it was the sending unit. The two wires had become brittle, and one had only a couple of strands still intact. So I dug some of the potting epoxy from around that wire to expose more of it, trimmed off the wire insulation on both leads, and re-soldered the two connections. Wrapped it tight with a bunch of electrical tape, and I think it will be fine. Speedo needle runs dead steady, and is accurate again.

thanks for the tip on where to look.

Michael