I have an 04 350 6.0 that i noticed a clicking sound under the dash. It seems to be a hazard/turn flasher relay located to the right of the steering wheel under the right lower dash panel. When i use the hazard button or turn signals it operates fine but when not in use it just chatters eratically (sometimes slow sometimes fast). I replaced the relay and swapped fuse #18 with another 20a fuse without any success. I have played with both the turn signals and hazard button to try and change the chatter and have wiggled all the wiring under the dash and around the fuse box with no change. I did pull fuse #18 and it stopped so i believe im checking the proper fuse. Any help pointing me in the right direction is appreciated. I checked the threads posted and didnt see it.

 

It sounds as if you could have possibly one of two conditions. Either the flasher is being energized by something unknown at this time or the flasher is on its way out. Suggest you try to find it and relpace it before it quits on you altogether . Then it can be somewhat difficult to locate since there will be no sounds coming from it and the hunt and poke method is very time consuming. If you ever want a real challenge try to locate a non working flasher in some of these vehicles especially when the flasher isn't where it is supposed to be.

 

I replaced it thinking it had to be bad. I have checked the voltage to the relay with a digital multimeter and the 12v was steady and I also checked the ground continuity and it appeared solid. No other voltage was detected accept the source from the fuse box. Dont know if i should get an analog meter to look for a quick variance in voltage? Thinking about trying a different source for the voltage. Will that diagnose a posible faulty new relay?

 

I believe there are only two ways to get that flasher to start working. Something in the steering column switch assy could be making intermittent contact causung the flasher to start clicking. Until we can pin it down, its only a theory. Are we positive it is a signal lite or Emergency flasher?
I have been up the road where aftermarket flashers don't always work correctly. The truck uses an electronic flasher and your best bet is to get one from Ford. They aren't cheap, but they usually do the job. If there are no other tell-tale clues visible, it might pay to get an OEM part.