brakedrum

I made an edit to the above post, adding a "1" that was hidden way on the bottom of the diode.

brakedrum

Ok. I'm now leaning towards making the wire splice. The warning indicator is worthless, anyway, if it's always on, so I might as well short it out at the source. This evening I replaced the last bulb (high mount) that is monitored on that system, and still have the dash light. Do you think there is any way to check continuity on those copper spools?

Nonio

Brakedrum, at this stage I could tell you to do this :

1 - Pull out both units ( brown and black )

2 - Open so the PBC is out of the plastic enclosure.

3 - Use an hairdrier to blow some hot air from a distance to send away any moisture that may be housed in there. Carefully and without overheating the PBC or the componentes, always hold the part in your hand to avoid doing so.

4 - Carefully undo and redo all the soldering contacts.

5 - Reinstall and check. If light is still on then yes, cut the wire and override the whole thing.

That's what I intend to do soon.

Nonio

And if you just solder a small jumper on the diode's legs would that make the bypass that would shut down the indicator light on the cluster for good ?

Nonio

BrakeDrum, I tried that today.

I connected the green/white wire on the right side sensor ( brown one ) to the black ground wire and ... guess what ?

The stop light fuse under the bonnet blew up.
Replaced the fuse and undid the connection and it didn't blow up again.

Would that be normal ?

brakedrum

Interesting. Glad the fuse did it's job. Having to rewire an Accord due to a fire would be no fun.

I did find that there is a Honda-approved test for the sensors (see link). My left sensor (brown) didn't make it past step two, so I took it out and used the continuity setting on my multimeter to check all kinds of connectors and solder joint on it. When I reinstalled it, I thought I fixed it because the dash light went out. It stayed out for 2 full days. I was about to come back here and post victory. Then, this evening, the light came back on and stayed on. Everything points right to that left sensor on mine. I've done nothing that should have created an "open" on the WHT-GRN wire between the brown sensor and the dash light, so later this week, I'm going to purchase a new brown sensor.

I used a T-bar pin (like are used in offices to put posters on cubicles) to back probe the plug on the WHT-GRN wire of the brown sensor. Sharp tip pushed in beside the wire far enough, touches the flow. Then I rigged alligator clips to the tips of my multimeter which I set for ohms. Clipped the red onto the T-bar pin and then found a ground with the black on the metal surrounding the light assembly. You'll know it's grounded when the ohms jump and stay steady. No ohms showing, then you haven't grounded the wire yet.

This link is Honda Service manual stuff, and pretty useful information:

https://dl.goodnet.com/dl/1209006/0/...ual/16-135.pdf

uberEFtuner

I had problems like this. I discovered that I had water inside that was shorting the warning circuit out. I had to disassemble everything and dry it out.

Nonio

I thank you for your dedication and cooperation.

I looked at the whole matter with more attemptive eyes and I did already stop by the auto electrician's a few times regarding this matter.

Having looked closed into this, I can now say that the matter is hmumidity/moisture-related and that there are at least two different symptoms that can be observed.

I say this because this last week was quite sunny in Portugal with quite hot days ( like late Spring/early Summer ) and the light on the dash did go out a few times these last few days. However, NEVER in the morning - always during the sunny afternoons.

So, here's what happens when I get into the car every single morning;

1 - As you turn the key on the ignition, the light is supposed to go out as the system does its diagnosis and only then, after you press on the brake pedal does the brake light come on, after faulty bulb detection.

It doesn't. As I turn the key the light is on and stays on. The system does NOT perform its check routine.

... or ...

2 - The system does perform the check routing but when the brake pedal is pushed the light does come on.
As the day grows hotter by the hour, the light will eventually go out and won't come on again until the next morning.

I forgot to mention before that all of this NEVER happens during the summer, this is a winter-only matter and that leads me to think it's definetly related to water or humidity somewhere inside the car.

uberEFtuner, where was it that you found water in this circuit and what did you do to end the matter ?

Thank you all once again.

uberEFtuner

My car also did the same thing. The light would be out when the car is started. Then after i drove down the road and hit the brake it would stay on.

I completely disassembled the little box that's attached to the tail light. Also I fixed the leak around the tail light gasket.

brakedrum

My light runs through the power on self test (post) just fine, but stays on sometimes. Sometimes it posts and then goes off. It posted this early morning and stayed on. A few hours later, I started the car and it posted and stayed off. Then about 5 miles into my drive, it came on. Again, the fickle behavior keeps pointing to that sensor and those copper spools in there causing random loss of ground on that system. Loss of ground in the loop that that WHT-GRN wire is on is the only thing that can make that brake lamp light on the dash stay on. I also want to ask the poster who found the moisture, where he found it. I have searched for moisture and cannot find any, however, I have not torn the whole trunk and cabin paneling apart to search crevices along the path of the wire.

Try running the tests that are in that PDF. I am going to post of picture of Page 5 where the details are found, but not sure if it will be legible, here. If not, refer to the pdf link in my prior post and go to page 5 after opening it. Curious to see what results you get.

brakedrum

Thanks. So you found moisture in the taillight assembly that was impacting a bulb fixture directly, or was causing residual dampness that was impacting a fixture?

Nonio

Ok, that's the end of the story for now.

Problem on the left sensor diagnosed with the help of the excerpt of the service manual published by BrakeDrum.

Bypassed it and all lights are out for quite some time, will remain like this until I find the time and mood for a replacement sensor.

I thank you all for your help

brakedrum

Glad you got it done. My light is still on, but only sometimes. I didn't replace the sensor, yet. Not going to worry about it for now. If I see a fresh 4th Gen at the junkyard I will surely pop in and ask if I can snag that sensor off of it if the price is right.

brakedrum

I had forgotten about posting in this thread. Glad it came back up. I tried junkyard diodes on both sides and that brake lamp indicator still comes on. The diodes are fine. The fault is somewhere else along the path from the diode to the dashboard. Possibly at the bulb itself on the dash. I do think the the problem is related to moisture or very moist air because although that light is on a lot, it's guaranteed to be on when it's raining. I just didn't have any more time to tear the dash, liners, etc. apart trying to find whatever little thing that has corroded.

brucepick

I had to deal with the brake bulb warning light after installing LED bulbs in the brake lights. The LED bulbs caused the bulb out warning to light up as they draw very little current. This thread and a couple others I found elsewhere were helpful.

I didn't understand immediately some of what I read. I needed it spelled out just a bit more detailed. I finally sorted it out.

Here's what worked for me:

I found the thin white wire with green stripe, where the wire harness bundle connects at the left side brake light housing. NOT the green wire with white stripe! That's the 12V power to the bulbs. You want the thin white with green stripe.

Snip the white wire with green stripe, about 2 inches back from the connector. Tape over the short piece attached to the connector; you can ignore it. Connect the other side of the wire you snipped, to ground. That's the "splice" you need.

I used a new thin wire (22 ga) that I spliced to the cut end of the white/green wire. I was able to slip the other end (insulation stripped of course) of the 22 ga wire into the back of that same connector, right where the black ground wire is. It made good enough contact to get rid of the dash warning light.

I taped the new wire into place along side the connector so it won't easily slip out of the hole. Taped up the rest so it's pretty clean. That's all.