On a 1998 you are due for your 2nd (At least) battery change so I'd do the following.
First, all the wires attached to the POSITIVE battery terminal, Wrap them up in red ribbon and tie them together.. Use black thread on the negative (if more than one wire) and then pull the batteries and take them to a battery store for testing.. Or just replace them.. I like Golf car battteries my curent ones are DEKA my Interstates lasted 10 years, TROAN are considered best.
On the rest of it.. No comment save "When changing batteries it never hurts to have the charging system checked as well".