Right rear brake light stopped working....

[coupe11]

Park light works, brake light doesn't.

Stopped and bought a couple bulbs at NAPA this morning.

Came home, replaced the bulb, still doesn't work. Tried the other one in the pack, still doesn't work.

Didn't have time, right then, to grab a multi meter and check for power/grounds. The vehicle has zero rust/corrosion under it. Right at 6 years old with 83,000 miles on it in NC.

I guess there's an issue with the wiring somewhere back in the body/along the frame??

Anyone else have this happen to them at some time?

I put the scanner on it (on my 05 Silverado that sucker checks the wiring systems, pretty cool how detailed it is) but on the Expedition it doesn't seem to check the various wiring systems.

One wild thing. When I ran the first scan if popped up with a power train system fault - stolen vehicle, immobilized. Been running fine for about 4 months now (since we bought it). Checked further and it was an old code. So I cleared it. Never expected to see that.

 

[Munkiebunz3]

Just to be sure, you tried those bulbs on the left side to verify that they work or swap left/right bulbs?
Otherwise, certainly does sound like a wiring problem. The wiring is usually channeled under the door sills then along the cargo trim. You're more likely to have problems closer to the light assembly than anywhere else.

 

[coupe11]

Last night my youngest son asked if I'd checked the fuses. He said Ford isn't bashful about using two fuses for the same size circuit GM would use just one on.

He's had an F350 for years and must have had to replace some fuses. He told me the fuses would not look like the ones I'm used to seeing.

I'll have to check that out later today.

No, I didn't try the bulbs on the left side. I can try that, too. I'll get the multi meter out, too.

 

[Plati]

I've even seen where the brass terminal in the connector to the light had backed out enough so it wasn't making connection and that light didn't work … didn't show up until months later after an accident. So it could be something other than wires.

 

[coupe11]

Well, it's working, again, for now. It was the park light, not the brake light. Some things are better verified without help from someone else (who knows what a light is, but not necessarily the difference between brake and park lights.

Anyway, it's a park light, not the brake light, or at least the park light circuit/filament in the bulb).

Checked the fuses, not the fuse.

Took both lenses off, swapped the bulbs, new bulb worked on the left, old bulb didn't work on the right (same bulb worked on the left side when it was in that socket).

Tried the old bulb, swapped around and wiggled the wires, nothing. Wiggled the wires again and suddenly it was working (wiggled at the socket). I wiggled, pulled, etc. and it just kept on working. I pulled harder. It kept on working. So I put all the bulbs back in the lenses and put them back on the Expedition and checked and they both still worked.

Put my stuff away and parked it.

 

[Plati]

Well, it's working, again, for now. It was the park light, not the brake light. Some things are better verified without help from someone else (who knows what a light is, but not necessarily the difference between brake and park lights.

Anyway, it's a park light, not the brake light, or at least the park light circuit/filament in the bulb).

Checked the fuses, not the fuse.

Took both lenses off, swapped the bulbs, new bulb worked on the left, old bulb didn't work on the right (same bulb worked on the left side when it was in that socket).

Tried the old bulb, swapped around and wiggled the wires, nothing. Wiggled the wires again and suddenly it was working (wiggled at the socket). I wiggled, pulled, etc. and it just kept on working. I pulled harder. It kept on working. So I put all the bulbs back in the lenses and put them back on the Expedition and checked and they both still worked.

Put my stuff away and parked it.

So, I'm thinking is some version of "what I said". Sometimes the brass terminal in the connector isn't seated in its position (locking tab) or sometimes it needs to be bent back a little (like a spring) so it'll make contact reliably. Older house lamp fixtures have that problem a lot.

My guess is you're gonna let it ride. Its working!!

 

[coupe11]

Oh yeah, I pulled the wires different directions and pulled "out" on all three and none popped loose and nothing stopped the light from working.

When it happens again I'll try to get the plug apart and see if I can see exactly which one is out of place.