WELA signed on the air on March 11, 1970 with the following jingle: (Drumroll) - Announcer: "You've listened to the rest, now listen to the best!" (Chorus - "W-E-L-A, You never heard it so good!") The original format consisted of music, mainly middle-of-the-road (MOR), adult contemporary and rock 'n roll oldies selections, with local news and information. The station made a name for itself with its coverage of an explosion at the Linden, NJ Bayway Refinery just after 11 PM Saturday December 5, 1970, which had area residents fearing for their lives much of the next day.
In January 1971, the station changed its call letters to WJDM, with the letters J, D and M standing for the first names of the original owners .
Later in its history, the station adopted an ethnic format to better cater to the city's changing demographics, expanding from Sundays only to every day by the 1990s. Later that decade, the station became the first in the United States to acquire a license to operate in the expanded AM radio broadcast band at 1660 kHz, carrying AAHS World Radio network children's format until 1997. Initially, the station carried the same WJDM call letters as its parent station, but later adopted WWRU and changed its city of license to Jersey City, New Jersey.