I belive it's a bad heater core but unsure was woundering if there is an easy way to check if that's the issue. The light for my 98 concorde is out as well working on fixing that. However the A/C and fan's work fine except when I try to turn on my heater only cold air come's out. All the fan's are working, all the fues's are fine and there is Coolant in the system. Looking for quick fix to last til after winter if possible.