Is there any way to bypass the dash light rheostat in the W123 cars so,let say will be on at high intensity allways,insted of dealing with the crapy mechanism,or replace it?

i have soldered a wire across the back of the rheostat that will bypass it

What you mean across the back?,between those two clamps that keep the rheostat in place,or between the copper bars on the back of the rheostat.

Either way would work. But it would be easier to do if you jumped the strips on the back of the rheostat. And less likely that you would mess up your indicator assembly. I have a good used W123 rheostat for sale. PM me if you want it.