In 1969, the call sign was changed to 2ZM and in 1973, 2ZM was joined with 1YD and 3ZM in Christchurch to form to youth orientated ZM network, 1YD then became 1ZM.

The first 2ZM breakfast DJ (6 am to 9 am) was Stewart Macpherson, who had just returned from broadcasting in the UK with both the BBC and Radio Luxembourg.

Using the show title 'Macphersonland', his innovations included introducing News Bulletins onto the station (despite management opposition), and a weekly published Top 40 chart available at leading music stores.

As the Mount Kaukau transmitter could not cover parts of the Hutt Valley effectively, the station continued to broadcast on AM until 1986, when a second transmitter at Towai (on the Wainuiomata Hill between Seaview and Wainuiomata) was commissioned broadcasting on 93.5 to cover the Hutt Valley.

In March 2007, ZM altered its Hutt Valley frequency from 93.5 to 90.9, to form a synchronous transmission with the signal from Mt Kaukau, also on 90.9.

This meant that commuters no longer had to switch their radio dials between the two frequencies when driving between Wellington and the Hutt Valley.

For the first year the ZM Morning Crew show ran from 6 am to 10 am in Wellington but finished an hour earlier in the rest of New Zealand.

Polly and Grant presented their nationwide breakfast show on The Hits from Wellington until they left in 2017, later moving to More FM.