Dash 8-300
Flight Crew Air Transport Pilot (ATP)
Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Aircraft Equipment Problem Dissipated; Flight Crew Overcame Equipment Problem
Aircraft
On approach to ZZZ; I called for gear down.  When the captain put the gear handle down; we got three red unsafe lights and 2 yellow lights on the gear handle.  The gear had not come down and we had no caution lights or any other indications.   We executed a missed approach so that we can complete the alternate gear extension procedure in the non-normal  checklist.  When the guard on the inhibit switch was lifted up (the inhibit switch was not yet touched); the gear came down.At that point; we had the three green lights on the glare shield and the landing gear alternate verification lights were also  green.   At that point; we told ATC that our issue was resolved and had a safe landing.   Side note: We ferried this plane to ZZZ1 and picked up another aircraft to fly to ZZZ2 and back to ZZZ3.  When we got back to ZZZ3; we talked to maintenance about the issue with aircraft.  They told us that it was a wiring issue that prevented the gear from coming down initially.
A Dash 8-300 First Officer reported that after putting the gear handle down; observed three red unsafe lights.