I have an '88 Ford Ranger 2wd 2.0l 5spd. Recently, I was informed that the brake lights weren't working. I checked the fuse, which was blown and replaced it. No big deal.

A day or two later, I noticed that now, every time I hit the brakes, the dash lights would come on. But now the tail lights weren't working. Again, checked and replaced a blown fuse for that, and was happy for the time being. Next, I noticed that, with the lights on, the left turn signal wouldn't work. Right one was fine. I replaced the flasher. Things worked for about an hour.

This has gone on now for two weeks, and the way things are right now are as follows. With the lights on, no left blinker. Right works fine. With lights off, both blinkers work. No brake lights, though the fuse is still, at the moment, good. When ever I hit the brakes, or the right turn signal, which still works with the lights on, I can hear a load being put on the engine, as if the alternator is struggling.

Of course, the guy at the parts store who checked my alternator, didn't seem to know exactly what he was doing. I read the display of his alternator tester, and it read a max amperage of 1.8 amps, which seems pretty low, but then his machine read "Diode pattern is good" which then cued him to say, "No, you're alternator is fine". If the alternator is bad, could that be the root of my turn signal/brake light issues?

I saw that a fellow named Hokie on a Harley posted something EXTREMELY similar to this, however there was no sure solution posted.

Anyone have any ideas?

 

Not that many people viewed or replied, but in the event that some poor schmuck is coming here via Google, I'll go ahead and toss what worked for me out there into the ether....

I took damn near the whole dash apart in an attempt to fit my fat, fumbly fingers into a position to unplug the headlight switch to see if that was the problem. My rationale was that, if the brake light fused failed to blow with the headlight switch unplugged, that must be the problem. Well, it still blew. Much like many things about doing your own car repair.

Next I replaced the brake pedal switch because, well, it was six bucks. Still no go.

Finally, when retracing the cables from the front of the car back, I noticed that the u-haul trailer wiring harness had burned up. Damn me for not checking closer the first time. I removed it from the light set up and Voila!

No blowy fusey.