What is this condenser used for?

BTW while reconditioning my dash I tested the condenser (capacitor) on the back.
I'm guessing the 648 on the back represents micro farrads and that's what I read on my meter!

View attachment 1716010828

View attachment 1716010829I had 2 more and they all tested the same. Not bad for 55 years in the brutal environment of a car!
I you have no way to test high voltage leakage, then they are not fully tested. Also, leaky ones sometimes indicate more than their actual capacitance.