Rules for writers, Tenth edition - Diana Hacker, Nancy Sommers 2021

Consider separating the clauses with a semicolon, colon, or dash
Revise run-on sentences
Grammar

When the independent clauses are closely related and their relation is clear without a coordinating conjunction, a semicolon is one acceptable method of revision. (see 35a.)

A semicolon is required between independent clauses that have been linked with a transitional expression (such as however, therefore, moreover, in fact, or for example). For a longer list, see 35b.

A colon or a dash may be more appropriate if the first independent clause introduces the second or if the second clause summarizes or explains the first. (see 36a and 40a.) In formal writing, the colon is usually preferred to the dash.

A colon is an appropriate method of revision if the first independent clause introduces a quoted sentence.