Solved High mount 3rd brake light issue.

[mekelly]

I noticed the right bulb was not illuminating on the high mount brake light (left bulb works fine) on my 1994 Explorer.

I replaced the right bulb, still wouldn't illuminate.

I replaced the whole lamp assembly (new Dorman part) with new bulbs. The left bulb illuminates, the right one still doesn't.

At this point I am completely stumped. There's obviously power going to the lamp assembly as the left bulb lights up fine. It's not the part as this is the 2nd one exhibiting the exact same symptom.

I can check to make sure it's getting 12V but the one bulb that's on, is burning bright.

Any other thoughts, troubleshooting ideas?

 

[BrooklynBay]

Check the wiring with a test light. Swap both bulbs, and flip the bulbs around.

 

[mekelly]

After some more troubleshooting, it's a design flaw with the Dorman part.

The plastic retainer clip for the right bulb doesn't hold the bulb firmly in place. The first little bump or vibration and the bulb moves a little, so it isn't making electrical contact any more, and goes out.

I verified this with two Dorman parts.

I ended up bending one of the copper contacts for the right bulb to ensure a tighter fit, problem solved.

The left bulb on both parts was held firmly in place on both Dorman parts. The design isn't as good as the original Ford part but with a little persuasion, I have two high brake lights again!

 

[BrooklynBay]

Thanks for the update! Your thread's title was updated, and now says solved in green letters.

 

[KEN's Exploder]

This dorman lamp assembly, is the entire break lamp with lens for a 1994? Rectangular in shape? Not been able to find one. What is the part number?

 

[mekelly]

It's DORMAN #923200 . It's available at RockAuto for$9.21.

 

[KEN's Exploder]

Thanks Mekelly, but I think that's just the lamp holder and not the lens. Looking for the lens housing.

 

[mekelly]

You're correct. It's just the bulb holder. I didn't have to replace the lens. I would check sites that specialize in supplying auto body shops. May not be available any more.