qfruge

I 'm having a problem with my 1996 F150 5.0 4x4... the Turn Signals stopped working properly and I need some help troubleshooting.

For a month or more, both of my turn signals have been blinking very fast but because I didn't have a bulb out, I didn't try to fix anything.

Now, Wednesday of this past week, I activated my turn signal but both signals would not work... I don't have any other problems with the emergency/hazard 4 way flashers, brake lights or backup lights or any other I started by checking fuses and I have now replaced the following items with new parts:

* Turn Signal Switch in the steering column
* Round Turn Signal Relay in the fuse box
* 4 x 3157 Turn Signal Bulbs (2x rear and 2x front)
* 2 x 3157 Reverse bulbs
* 2 x 194 Front Side Marker bulbs

While making these repairs I disconnected the battery and after it was reconnected I was able to get my signals to flash very slowly 3 to 5 times and then it stopped again. Sometimes it would only flash 1 time and stop or other times it would not activate at all but I could hear the relay click and feel the relay attempt to activate my turn signals. Any thoughts on what I should look for?

kd3pc

the fast blinking is usually related to bad grounds...the rear is notorious for dirt/crud collecting on the connectors, and if someone added a tow hitch and trailer light/plug....it could be there.

Each light needs a solid 12vDC and a solid ground.

easy way to test is to make a "ground" jumper with alligator clips and go to each socket and ground it specifically and see if the fast blink returns to normal. I would start with the various ground straps that come stock...there is a recent post here about that.

Chris_1

iTrader: (1)

Check the ground to the rad saddle in front of the washer bottle - if you disconnect that, you get no tail lights (at least them for sure) so first thing to check - clean it up with sandpaper and then make sure it's tight.
After that you can start looking for bad spots in the harness wiring to the back and as kd3pc said, check the trailer wiring.

qfruge

I cleaned up 2 different grounds and bingo! Turn signals are working normal again. I also wrapped the trailer light to make sure it wasn't causing the problems. Thanks for the help!

Chris_1

iTrader: (1)

Good. Which 2 grounds did you clean up ?

qfruge

Okay... Not fixed...but better.

I noticed pulling out of my driveway that my ABS light came on every time. I could get it to clear by putting on the right turn signal momentarily.

The ground connections that I cleaned were just behind the wiper/radiator bottle and the other was just to the side of the battery. I wrapped the trailer wiring in split wire loop. It looks like I might be having an intermittent electrical issue.

nayrb64

Might help......

qfruge

My truck didn't like the 2x Sylvania Zevo 3157 LED bulbs in my rear tail lights. They looked good but I replaced them with standard Sylvania $5 bulbs and all my troubles went away.

seschenburg

If you use LEDs in your signal lights you need a load resister too.

Engage the signals and have a friend stand behind the truck while you move the wires in suspect locations. When the lights start working you've found the location of the problem.