Electrical spike to instruments

[schueymcfee]

I've heard of other owners having this problem.

Both the speedo and tacho go around the clock and back when the ignition is switched off.

They're not meant to do that are they?

What can I do to prevent it.

Thanks.

[spend]

Mine does it only when the heater blower is switched on. (its on the same circuit as the dash instruments).

Dave