After receiving his B.A. in Economics, Dyer taught school for seven years. In 1974, he became a research economist with the International Brotherhood of Electrical Workers.

While at the IBEW, he served as OPEIU, Local 2 Chief Shop Steward. In 1975, Dyer was elected to the Local 2 Executive Board and in 1984 as First Vice President of the Local. In 1985, he became a fulltime Staff Representative of Local 2, and in 1993 was elected President of the Local. At the 21st Triennial Convention, Dyer was elected Vice President of Region II.

In addition to serving as President of OPEIU Local 2, Dyer serves as a Vice President of the Maryland State and D.C. AFLCIO, as a member of the Executive Board of the Metropolitan Washington Council of Unions, AFLCIO, and as President of the Board of the AFLCIO Credit Union.