2008 6.4L F250 4x4, replaced front and rear running lamps, turn and stop lamps with LED probably 2 years ago. did not wire in resistors. always checked lights for function when hooking up trailers. never noticed any problem until 3 or 4 months ago maybe. connected trailer all lights functioned at start, got back after dark and noticed right stop and turn not working. running lights were good. trailer is also full LED. started paying attention and the lights would begin to function by only cycling ignition so not fuse problem. problem would move around turn signal did not work on one side but worked on the other. brake light same symptom never had both sides out at same time. today right rear stop light out, running light and turn both working. switch bulbs side to side and same bulb did not work on left rear stop light and right did work. thought some how LED bulb failed. bought 2 pack 3157s replaced both and then both right and left running and stop lights not working, turn signals work and that's where i'm stuck.

all front lamps function normal. mini fuses 12,13 under hood for brake system both good. trailer fuses good. removed brake switch at pedal opened up found clean contacts, unplug rear harness connector at bumper check and clean. have same symptoms now with old and new bulbs first set were phillips and new set are sylvania.

currently no stop lamps, no rear running lamps, rear turn signals work both sides. stumped looking for help

 

Hey Robby, welcome to ford-trucks.com if you haven't been already!
I don't know anything about your problem, but have heard of others and seem to remember discussions highlighting possible solutions. So back to the top to see who salutes!

Good luck.
I hate those "it worked before, but not now" issues!

Paul

 

Thx to all concerned. here's an update.

I continued to tinker and rotated both LED bulbs 180 degrees and problem solved. I didn't think about the LED polarity. If it remains corrected I was unlucky enough to have purchased the new bulbs and installed them both 180 out after discovering my initial problem. That would explain why I initially found the only right rear not functioning and the left rear did, but installed new bulbs and both went out. I had swapped the old bulbs and bad luck prevailed and the left rear didn't work and the right rear did. Apparently, I just plugged the same bulb from the right 180 out on the left and then got the bulb correct on the right rear by chance.

If things remain corrected I didn't think about the polarity when I initially installed the firt set of LED bulbs two years ago and got the right rear wrong and the left rear correct. Each time I plug in the low floor trailer I could only see the left rear trailer light figured all was good. I could swear I had seen both working at night. I apparently was lucky enough to get the polarity correct on both the front bulbs. I can return the multifunction switch to Autozone and my only investment to a lesson learned is the $15 brake pedal switch I'll leave in.

I hope it's that easy. Rob

 

That's great! Thanks for the update.
You know, I've heard this so many times about the polarity of these things, and yet after all these years I still forget to mention it in discussions! One of these days I'm going to remember and help someone save some time and hair pulling.

Paul

 

Paul, i wish you had remembered too and you were the first one to have read my post, laughing. It's messing with my head. I ask my father who is around this truck a lot if in fact all these lights had been working and he agreed they had. i went to youtube and found a kid lighting LED car bulbs in reverse polarity.

not something i'll forget a second time.

 

And now we'll have to apply that memory to those who's lights worked properly for a couple of years first as well!
Sheesh, the clues just never stop morphing and keeping us on our toes. It's like u-joint failures. Never the same clue twice.

Paul

 

Thx for your interest Paul. The real stumper for me is if LED polarity was the only problem then why did both rear turn signals work but both brake lights did not? It was just one side acting up until I unfortunately plugged two new bulbs in and got both bulb polarity incorrect and then both brakes didn't function.

However, I just checked for proper function and all is still good.

Thx again, Rob