So with 172,000 miles my truck has started a new trick. When I turn on the turn signals they’ll flash or interrupt normally for a few times then stop. After I turn the signal lever off and back on again they start to flash again only to stop after several times. This happens to both the left and right hand sides. The emergency flashers seem to work alright.

Is this a function of the indicator flasher SF631? If so, were exactly is it located?

 

Hmmmm could be your flasher under the dash on drivers side,,,maybe someone else will chime in and tell you more

 

Interesting....mine does/did this too! The flasher is a yellow unit under the knee bolster left of the steering wheel. It is easier to get to if you remove the plastic and steel panel under the steering wheel. then you can't miss it. Mine was doing this a few months ago and now works OK.

 

If you have a separate flasher mounted to the fuse panel, they can fail over time. The bi-metal spring inside that makes-breaks the contact to operate the lights can get weak and stay in contact, leaving the bulbs lit with no flashing going on. Most fail in the 'connected' position, and will not open.
If you do not have a separate flasher, then your computer is doing the flashing. It may be in the GEM or SJB, vintage dependent, with a separate relay doing the 'switch' function, I think one per side, but don't bet any donuts on that.
tom

 

I don't remember if the emergency 4 way flashers worked or not (I think they did!) when I bought my 99 (manufactured in late 98) Ranger, but neither turn signal worked at all. What I found was that a terminal had come loose in the connector that plugs into the multi-function switch (turn signal/wiper/high beam lever) and once I fixed that the left and right turn signals came back to life. You might ought to take a look at yours, just in case it's that simple.

Inside the connector shell, each terminal pin is held in by a plastic tab. One of these had broken off and allowed one of the terminals to back out, so I put it back in place and wedged a piece of plastic or something into the terminal cavity to hold it in place. Easy fix and costed me nothing! Actually it saved me some money because I used the non working turn signals to negotiate on price when I bought the truck.

 

There is a chance it's the flasher but most likely, you will be replacing the multifunction switch to solve the problem.

Edit: On your MY, it is possible to disassemble and clean the multifunction switch.