Darrenbret

So I had two brake lights out. I replaced the first bulb and that light works fine now. But after changing the second bulb, on the other side, that light didn't come on. I switched out bulbs and no luck. So it's not a bulb issue with the one light Also checked the #37 fuse on the driver side fusebox, and the fuse is fine. What could it be?

salimshah

It can be the wire or socket is bad/corroded.

Salim

Drcoffee

+1

Test the sockets for power.

thaeleelyr

When you say it isn't coming on, do you mean it doesn't come on when you press the brake pedal or it isn't on all the time or both?

Darrenbret

I mean it doesn't come on when I press the brake pedal. I don't see any visual corrosion either.

salimshah

Check the wire folds on the bulb. Align them with the connector metal.

Take a voltmeter and see if you get voltage on the tabs of the connector. You may have to trace the wires to the it next junction point.

I dont like the device but the trailer installer have a device that punches through the insulation to touch the conductor inside the wire. You can make one by using a fine needle, but make sure you dont short things out.

Salim

thaeleelyr

There are two filaments in these bulbs - one for the constant "on" of the tail light and on that comes on when you press the brake. When you turn on your lights the bulb should be on constantly. Does it?

Also, not counting the "third" brake light there are four lights total. Each side has two brake lamps - one on the hatch with the reverse lights and one on the frame with the turn signal/hazard lights. Which one is the issue and on which side (driver/passenger)

I hate to ask this, but just in case, did you double check the bulb number? There are two on the rear, 4770 (single filament) and 4773 (double filament). They look exactly alike. The double filament is a bit bigger and can't be used by mistake but you can accidentally install the single filament in the brake light, which will result in no lighting when the brake is depressed.

Also, are any other lights out, like your reverse or license plate?

Darrenbret

Thanks for helping! So, hold up, are you saying the bulbs for different back brake lights are not the same? I assumed - perhaps stupidly! - that they were. I bought a two pack of bulbs. The first bulb I replaced was the outer brake light. That worked - when I checked by applying brakes the light came on. But the second bulb that I put into the inner, other side brake light - the one on the actual door when you open it - didn't light up. I switched out the bulbs to make sure it wasn't a bad bulb - but it never occurred to me that the two lights would take a different bulb. Is that the case?

I will also check the other things you suggested (overall lights and such) when I'm back at home later today.

Thanks again for the help!

Darrenbret

Mission accomplished. Different filament bulb was the issue. All four brake lights now working. Thanks all for the help! Much appreciated.

thaeleelyr

You're welcome! I'm glad it was something simple. You're not alone in making that mistake *a-hem* looks in mirror .
Fortunately, it's a memorable one, lol.