"Family comes first and that is the big motivator to return. I want to be able to help my mum more," Ranger said.
"Last time I travelled from Northland and lived on my own. Our family wants to be together in one place and, from that point, I have decided to play for North Harbour."
Northland Rugby chief executive Jeremy Parkinson said news of Ranger's decision was made clear to him three weeks ago.
However, Parkinson asserts the loss of one of Northland Rugby's favourite sons is not a setback to the province and to ITM Cup aspirations.
"We've been in discussions with Rene over the last three weeks. We put our best hand forward, which we believe was on par with North Harbour. But Rene's got a young family and it was a case of what was best for his partner and little girl, so we totally respect that.
"We didn't have Rene last year and we had the best season we've had on the field for 10 years.
"It would have been good to get him back, he would have added value ... "We wish him all the best and when it's time for him to come home, our door's always open."
North Harbour coach Steve Jackson is excited by Ranger's decision, with the Montpellier player set to add considerably to his backline.
"He is a quality footballer and he has that X factor," Jackson said. "He will provide real leadership to the backs off the field and on it he has the ability to break open a game at any time."
Ranger also has a firm focus on again pushing for an All Blacks spot.
New Zealand Rugby chief executive Steve Tew said: "He's a classy player with the ability to surprise that makes him a favourite of fans. He will have learned much from his time in France and is sure to be an exciting drawcard for the Blues and North Harbour."
Ranger will return mid-year.
