When I turn the ignition on my speedo spikes at 160 mph and the odometer does not work. I've had the speedo and wiring checked and they say there's nothing wrong. Think some is wrong.
Any ideas?
Thanks

it might be an overvoltage protection relay issue. 107 speedos usually dance about if there are battery.voltage problems.
Get a Digital volt meter and check the volatge accross the batt terminals with ignition off, on and then engine running through the rev range. it should be not lower than about 10.8 before the abs goes haywire. over 12 volts from battery alone perhaps a bit less with just ignition on, and at least 13.5 with the engine running, up to about 14.5 full output from the alternator.

Thanks
Will try that

MyrosII
Checked voltage as you sugessted. Everything ok.
Still the same.
Thanks anyway.
Guess I'm going to have someone else look at speedo

I don't know if it is a voltage problem but my gas gauge fickers every now and then as if there is a voltage surge. Any ideas?
1982 380sl

Had the same problem but all my cluster flipped.
Found a loose groundwire. Don't know if that's your problem but worth a try.