Brake light question - 2003 Honda Accord

[RagingBITCH]

Ok my buddy was following me today and noticed my four brake lights on the trunk did not turn on when I tapped the brakes. My fifth brake light (under the rear windshield) did turn on, but the four on the trunk did not.

When I hit the unlock button on my car, those four bulbs do turn on, as well as when I have my headlights on. I'm assuming they turn on brighter when the brake lights are tapped, as nothing happens when I press on the brake lights.

I checked all fuses both in the car and under the hood (regardless of whether it belongs to the lighting system or not) and did not find any broken fuses. I'm stumped as to what this might be...anyone have any ideas? Thanks!


Mel

 

[SSSnail]

Which ones are you talking about? Take picture.

 

[Zenmervolt]

Combination brake/running lights run dual-filament bulbs. It's actually very common for the higher wattage filaments to burn out before the low wattage filaments which will leave the lower-wattage running light filaments functioning. I have also seen people force single-filament bulbs into holders designed for dual-filament bulbs which can also screw with things in the way you describe.

It's also possible that the live wire has a short somewhere that isn't allowing the trunk-mounted brake lights to come on.

ZV

 

[SSSnail]

That, was the most BS PI call I've seen this season.

 

[BassBomb]

That, was the most BS PI call I've seen this season.

what?

 

[RagingBITCH]

Combination brake/running lights run dual-filament bulbs. It's actually very common for the higher wattage filaments to burn out before the low wattage filaments which will leave the lower-wattage running light filaments functioning. I have also seen people force single-filament bulbs into holders designed for dual-filament bulbs which can also screw with things in the way you describe.

It's also possible that the live wire has a short somewhere that isn't allowing the trunk-mounted brake lights to come on.

ZV

Hmm, how do I check for the short? Sorry that's a stupid question In regards to your first - I just find it hard to believe all 4 higher wattage burned out at the same time, unless that's pretty common. Thanks ZV!

 

[woodie1]

It might be as simple as the brake pedal switch or the wires going to it.

 

[Zenmervolt]

It might be as simple as the brake pedal switch or the wires going to it.

Nope, he said that the CHMSL (Center High Mounted Stop Lamp) is still activating, so the switch itself must still be good.

Hmm, how do I check for the short? Sorry that's a stupid question In regards to your first - I just find it hard to believe all 4 higher wattage burned out at the same time, unless that's pretty common. Thanks ZV!

Honestly, finding a short would be a royal pain. To check, you just need a multimeter. Touch the multimeter leads to the contacts in the bulb socket and check to make sure that you're getting 12 volts (or thereabouts) when the brake pedal is pressed (having someone else to hit the brakes is helpful here). The car doesn't need to be running, just have the ignition in the "Run" position without starting the engine. Alternately, you could just buy a brand new bulb and use it to test each socket since you'd know it was good.

The contacts at the base of the bulb are usually the + terminals while the sides of the socket are the ground, which is shared by both the low and high-wattage filaments. So you have 1 high wattage contact on the base, 1 low-wattage contact on the base, and the side is the shared ground. Since the low-wattage filaments are illuminating, the ground must be good, so if there is a problem, it will be on the + side of the wiring.

All 4 high-wattage filaments blowing out at the same time would be uncommon, but I can see a situation where, over the course of a 6-12 months they all wore out one after another and it just wasn't noticed until all 4 had burnt out. Chances are that they've all been installed for the same amount of time.

I would do the following:

1) Make sure that the bulbs currently in the sockets are the correct bulbs (it's possible that a previous owner used the wrong type even if they are dual filament; it's very important to use exactly the bulb type specified).

2) If the bulbs are correct, buy a replacement and test it in each of the 4 sockets in turn. (Or use a multimeter.)

3) If you tried the bulb and it didn't work, check to make sure all the contacts in the sockets are clean and that the bulb's contacts are able to come in contact with the socket's contacts.

4) If there's just no juice at all for the higher-wattage contacts in the sockets, I'd pass it off to a professional to deal with simply because I hate fishing through wiring and I'd rather pay someone else to deal with that crap.

ZV

 

[thomsbrain]

I'm willing to bet he just has burnt-out bulbs. If you don't have anyone driving behind you once in a while, it's pretty hard to notice it yourself unless you see your reflection on something as you back up. I personally recently burnt out the CHMSL in my own 2003 Accord.

The old 5th-generation Accord came with a special warning lamp when a brake light went out. I don't know why got rid of it since it was a smart safety feature.

 

[Zenmervolt]

The old 5th-generation Accord came with a special warning lamp when a brake light went out. I don't know why got rid of it since it was a smart safety feature.

3rd and 4th gen had this as well. So does my father's new Pilot. I'm kind of surprised to hear that it was omitted from the newer Accords.

ZV

 

[jaedaliu]

<-- snip -->

2) If the bulbs are correct, buy a replacement and test it in each of the 4 sockets in turn. (Or use a multimeter.)

<-- snip-->

ZV

Do this first. it costs $5? $10? to get 2 new brake bulbs. or buy 4 at once. as mentioned above, all 4 probably didn't go out at the same time, you may never have known that they were out if your friend wasn't following you. In that case, you might be posting a all 5 of my brake lights don't work thread.

 

[RagingBITCH]

3rd and 4th gen had this as well. So does my father's new Pilot. I'm kind of surprised to hear that it was omitted from the newer Accords.

ZV

IIRC, the cruise control stops working when a brake lightbulb on Hondas go out. I remember reading that on V6P.net a long time ago. (Or might have been another brand of car, forgot which one)

Thanks for the rec ZV and jaed...will pickup 4 new bulbs tonight and try it out.

 

[brblx]

check for voltage at the bulb sockets. if 12v does not appear when you hit the brake pedal, check the fuses. then check them again. it's probably a fuse.