Turn signals not working 2003 F150
Hi, my blinkers started off blinking a few times then stopped working, now they don’t work at all. The fuse says it goes to the brake lamps, hazards and turn signals. The hazards work as well as the brake lamps. I found the relay/flasher box and it appears the relay and flasher is the same for both the turn signals and the hazards. I checked for the wire/connector problem in the column and all looks good there. When I activate the turn signal lever I feel one click in the relay/flasher which leads me to believe the turn signal switch is working. I went ahead and replaced the relay with no results. Is the flasher internals the same for both the hazards and the turn signals or is there two independent sections inside for each? Thanks in advance for any Ideas, Rob.
I had already checked the switch, wires, grounds, fuses, circuit 15 and 30 power nine ways to Sunday with my multimeter. I am a BMW and Mercedes Tech, I just didn't have actual wiring diagrams or function descriptions so I had to go with wire colors and instinct. I took the cover off of the flasher to determine how it worked and saw a circuit board. Since it was not in an easily accessible place I didn't want to disassemble a friends truck to check it so I bought a new one from the dealer and it got better. Thanks again.
It is up under the dash between the radio/A/C control and steering column, closer to right under the radio. The relay and flasher are in a mount together. It was either a small bolt or one of those push in plastic retainers that I had to release to bring it down to right under the dash by the gas pedal. The lid to the mounting bracket was just a snap off situation. The smaller one is the relay, mine was black which is probably OK, right next to it is the larger flasher, mine was blue. About $35 from the dealer, the parts store only had a relay. You have to pop the blue cover off to see the circuit board.
Thanks Compwrench!
My 99 F150 had the same problem. Turn signals would not work but, the hazards worked fine. Found the flasher/relay box where you said it would be. Replaced the BLUE flasher ($15.99 at Autozone). Works perfectly! Many thanks!
Glad this thread was still around...12 years later!
2003 F150 was experiencing the same symptoms, hazards worked but directional blinkers were intermittent at best. Started with multi-function switch (ordered online) - no change; then relay - no change; then flasher unit - SOLVED! Really glad this forum and thread was here to help - 12 years after the last post! Good thing to know is the one blade that is perpendicular to the edges on both the relay and flasher point to the rear of the vehicle/toward driver seat. Total time was about 2.5 hours including two trips to the part's store for the relay and flasher, each were ~$20.


