Combustion instrument spins…

Hello friends the following problem has appeared for about 1-2 weeks with my moose: (S60, Bj12/2002, 2,4L 170hp, 110 ́000KM): Suddenly during the journey the whole instrument cluster runs out completely for approx. 1.sec, all hands go to zero, then everything goes up again. This happens about 10 times, within 5 min, then was again 4 days rest, no problems, then again 10 times happens, then again 3 days rest and so on. So far I have made the following observations: 1. or is (thanks to God) not affected, so car continues to run as if nix is 2. AbyssingLight (at least I could regulate it) also no change 3.Blinker noise (klackKlack) suspends for a short time! 4.Calculation of the on-board computer over residual tank-rich-wide is null and is recalculated, average consumption remains stored 5.ritt both during the journey and in standstill. 6.Tritt both in warm as well as wet cold weather on Mine you the combo is h in, so topic cold soldering point etc? Or could this also be due to a weak battery (should probably not be so fit anymore according to the last inspection… or to find the error elsewhere? Thank you for your advice! Stefan