Intrument cluster goes nuts

Hi.
2002 f-150 xlt 4x4 instrument cluster goes nuts for 3 seconds at start up and then returns to normal for the duration of the drive.
Speedometer pegs itself as far as it will go
Tachometer does the same as do all the other gauges, then after three seconds all is normal.
The engine acts normal the whole time.
This started about two years ago and would do it 1 out of 100 start ups, but within the last month at least 1 out of 5 start ups.

All factory parts by the way

I searched but found no threads pertaining to this.
Thanks.
Robert