Engine warning light, fault fan not working.

Bailey Advance 665 Peugeot Cab bought from new 2015 8500 miles. Engine warning light on, fault stored diagnosed as No2 engine fan not working, however fan tested as OK. Garage on advice from other Garage changed engine bay fuse box, initially cleared the fault and van returned after road test but warning light returned next morning. Van in limp mode but going to a specialist auto electric garage on Wednesday courtesy of the AA. Any one had similar problem and how fixed?