I dont know if the two are related, or if it just so happened to be at the same time. I am borrowing my dads truck (97 F-150, 4.6L) and driving it home, noticed turn signals werent working. Checking, the brake lights also arent working. Around the same time, I noticed the ABS dash light came on.
So I checked all the obvious things, checked the fuses (ALL of them, even those not directly related...) as well as the mini/maxi fuses in the fuse block under the hood. Checked the connection of the mfs behind the dash as well as brake pedal position sensor, all seemed tight. Reset the battery, etc. I did a visual inspection as best I could of all the wiring connectors behind the dash but there could always be something I'm missing. Luckily his truck doesnt have any electrical accessories like my old truck did so its about a thousand times easier, LOL.

So far though, no luck witha nything. Turn signals don't flash front or rear or on the gauge, brake lights dont work... reverse lights do work though so it doesn't appear to be a problem with any damaged wiring between front and rear, but who knows. headlights also work. All functions of the gauges (speedometer, fuel gauge, etc.) work fine.

Any ideas?

 

I think I've narrowed it down (at least hte turn signal/brake light issue) to the multi-function switch. If I wiggle the hazards just right I can use the turn signals and the brake light, but can't seem to get it to "stick" so will plan on replacing it once the ford parts dealership opens up and I can pay I'm sure entirely too much for it...

 

On my 97 F150 I have two fuse positions that had intermittent connections to the fuses in the fuse panel. One was for the brake/turn signals and the other was for the wiper motor. In each case to increase the pressure on the fuse contacts, I twisted the fuse terminals a little and plugged the fuse back in.