hi guys new to this forum seeking some advice and help!

i got a sierra sapphire with a 2.0 silvertop zetec conversion all been converted by someone else and everything else runs fine on it, carbs, megajolt, ecu and everything. its had a twin fan conversion done but fans dont kick in at all no matter how hot it gets, temp gauge works and fans work so im just wondering if anyone else had this issue? could it be a relay or coolant temp sensor? any advice cheers guys