1998 Mercury Grand Marquis Q&A
1998 Mercury Grand Marquis Question: why is my turn signal flasher irratic?
. . - pushrod
As you will notice there is no separate turn signal flasher for this year. The flasher is built in to the lighting controller. I had the exact same problem with my 1998 Grand Marquis LS. The lights are flashing fast because of the current draw on the wire run. I bet if you turn off the blower on your AC (turn off controls) you will notice that the lights flash at normal pace again. As the blower motor goes faster (higher fan speed) the light flash fast too. 2 Solutions: 1) CHEAP - Ignore it or turn down the blower motor speed when using turn signal 2) Follow Ford Service Bulletin for this problem which tells the tech to rewire the flasher circuit to not share a common draw which looked like a pain in the butt but it will solve the problem. - electronicbuff