1999 Mercury Grand Marquis has heat but does not blow out ... what could be the problem
Blower fan no good, could be a the fan speed resistor switch.
The fan speed resister switch failed on my '01 GrMq about two years ago. At first fan would blow at only one speed no matter the position of the fan switch, then it stopped blowing at all - I guess when the fan speed resister switch totally failed. I believe it should be easy to replace after removing the plastic HVAC shroud under dash on the passenger side (on my '01 - yours may differ). I had the dealership do it b/c I thought the fan may have failed. Bad choice - not cheap!!!
Search Mercury Grand Marquis Questions
Mercury Grand Marquis Experts