Commercial Fixed Wing
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Confusion
Deviation / Discrepancy - Procedural Clearance; Ground Event / Encounter Ground Equipment Issue; Ground Incursion Taxiway
General None Reported / Taken
Airport
Pushed back from gate at CLT. Ramp cleared us to spot X; approaching X I switched us to ground on 121.8 as directed and then we were cleared to proceed to Runway 36C via Golf; right turn onto (closed) Runway 5; hold short of Bravo. Instead of proceeding onto Golf we made a slight left onto Taxiway Romeo to join Runway 5. It was dark outside and the taxiway sign for Golf was not illuminated; we had seen the illuminated taxiway directional sign for Golf sitting to the right of Runway 5. Due to the nature of spot X being in between taxiways Romeo and Golf and the fact that the taxiway sign was not illuminated we mistook Romeo for Golf and contacted Ground to clarify new routing. The rest of the taxi and flight concluded normally.
We pushed back from gate in CLT; started engine 1 and began to taxi out to spot X. Before reaching X; to stay ahead of other traffic calls; the FO (First Officer) called Ground of our approaching location. Ground had told us to 'taxi via G; Runway 5; and hold short of B; and contact 121.8.' Having not made the turn yet I had seen a lit up Golf sign in front of me I began to continue forward thinking it was Golf. It was not until being in the middle of R that I realized that all other Golf lights were out and the Golf we had seen was actually a turn-off sign for Runway 23/5; not the actual taxiway we were on. I queried with Ground that we may have taken taken the wrong taxiway and that we were on Romeo instead of Golf. 121.8 had simply responded to 'continue on to Runway 5; left turn E and taxi to Runway 36C.' The taxi to the runway and the flight continued without incident.
Air carrier flight crew reported taxiway signage not illuminated at CLT contributed to a taxiway incursion.