Bouncing ELECTRONIC Speedometer?

Wise and knowledgeable KZ/Z/GPZ experts! The speedo on my wife's '81 GPZ1100 bounces all over the place. No worries, I've seen this before! pull the cable and liner, give 'er a good clean and lube and done!

No way! This speedo is electronic! It has 3 wires going from the speedo drive unit to the speedo! What gives? What do I have to do to get my wife's speed indication sorted out? How many other Kaws were made this way!

Thanks in advance for your help! Paul

You still need the basics, good power and ground connections, and of course the speed sensor signal from the front wheel. There is a test for the voltage the speed sensor makes while having the front tire in the air and rotating slowly.
I'd be checking all the connections to the speedo and sensor first before getting into it to far.
Do you have a Service manual for the GPZ? If not there may be a link here on KZR for a free download. Or I would think most of the tests for the 81-83 K/ LTD and the A/ Sport Touring shafty would be the same. But they do use a different speedo head. There are free links to those manuals.
www.kawiworld.com/index.php?option=com_c...icle&id=77&Itemid=99