Help With Defective Brake Light Failure Sensor

Great forum, new poster here.
I have a 1986 Honda Accord with only 66K, original owner and always garaged.
My problem is that recently the brake light failure light remains on. In the past this circuit was functioning properly and by changing a bulb corrected the problem, but not this time.
I checked the lights and found one of the four bulbs was not working, it was on the passenger side inner socket.
There are a total of 4 brake light bulbs, and one mounted within the glass on the rear deck.
I replaced the bulb but still would not work. I checked the circuit and found no current to the positive side of the socket.
Upon further tests I discovered there was no current coming from the sensor terminal to that bulb. Did a test on the drivers side sensor and found current going to both bulbs.

I determined it was a faulty sensor, all other lights work. In the sticky section of the forum I was able to download the service manuals for 86-89 Accords, thank you, a very good find. However, the sensors wiring diagram does not match that of my vehicle. They show two sensors in section 25-68, one for a hatchback indicating 5 sensor contacts, the other for a sedan (mine) indicating 4 sensor contacts, mine has 6 contacts so I’m unable to perform the tests described.

Being that the car is 22 years old,I can’t seem to locate a new sensor on the web, the local junkyards here are very consumer unfriendly, they will not sell small parts. I was able to solder a small piece of wire from the working terminal to the defective one on the circuit board of the sensor, this got the defective brake light to work, but the light remains lit on the dashboard.
Without dismantling the dashboard, I need to know what wire to cut or ground out to disable the light, I don’t need it since everything works properly. Pulling a fuse won’t work since it is shared by other circuits.
I’m assuming that light comes on when there is no continuity for a ground somewhere on the sensor terminals, I just need to know which one to ground out without doing further damage or blowing fuses.

Any suggestions on how to disable the bulb on the dash are sincerely appreciated.

nothing to worry about its a common prob found in hondas as long as ur tail lights are working i wouldnt worry my 93 accord does that too its just a flaw but ill take a flaw for 38 mpg anyday

Thanks for the reply and informing it's a common problem.
I just find it annoying having that red light on continuously.
I worked on it some more today only to discover that each of the six wires going to the sensor has a purpose and it's not related to the dash light.
1- For Directonal
2- For Tail Light
3 & 4 are for the two stop lamps
5- is a ground
6- is power source from brake switch on pedal

So it looks like I was wrong about some sort of ground malfunctioning causing the light to stay on. Nothing I can do at the harness in the trunk to deactivate it since all wires activate a light, there are no extra wires that I'm aware of that go back to the dash light.

quick fix put a piece of black tape on the light lol not annoying no more

6 wires going to the sensor is right according to my book. I suggest you use wire colors rather then terminal numbers. The W/G wire goes to the safety indicator and is activated when one of the lights fed from the brake light failure sensor is not drawing sufficient current when activated. So bypassing the sensor will not draw current through the sensor and the failure light comes on. If you disconnect either the black (ground) or the W/G wire, the sensor should be isolated from the safety indicator. Other colors of interest is the G/W which supplies power to the lights through the sensor and the other G/Ws which go from the sensor to the brake lights.

@mpumas
Many thanks for your reply. I'd like to clarify my last post, those were not terminal numbers I was describing, it was merely the total amount of wires and their function. My apologies, I must say I was not very good at my description since some of those I described were not form the sensor itself but within the harness going to the various lights.

The color codes you describe is what I have going to ther sensor.

In the bottom of the connector, the Grn\Blue is the power from the brake switch, however you indicate it to be Green\White. The two Grn\ Wht wires next to it are the two brake light wires. These are the two connecting points on the circuit board that I jumped by soldering a small piece of wire to get the malfunctioning light working.

I will follow your suggestion and disconnect the black wire from the connector, if that doesn't work I'll try the Wht\Grn, both located on the top part of the connection.

One more favor if you don't mind. I'd rather not cut the wire, but rather remove it from the plastic receptacle. I tried using a small blade screwdriver, then a thick sewing needle to free the protruding clasp but had no luck in freeing it.
Do I need a special tool or is there another trick in pulling the wire from the receptacle.

Your help was genuinely appreciated.

It it is like a Mollex plug and requires a special tool to collapse the barbs. Entry is through the side that plugs into the sensor I think. If you are at circuit board level, can you see the reed relays? They are tubes with wire wrapped around them. The wire that is wrapped around the relays is the wire that goes to the brake light. If you cannot fix the board, you might consider cutting the trace. It is easily fiixed if you want to bring it back to OEM configuration.

Thanks for advising about the special tool, I'll check the auto parts stores some time this week and see if I can get one, if not I'll cut the black wire.

Yes I saw three reed relays on the circuit board. I was confused when I tested them since I got no continuity when I touched the two thin wires on each side of them going to the circuit board. Nor did I get any continuity from them when touching one end of the coil to the other. Appears they have a coating on them so I wouldn't have metal to metal contact, but for sure I thought there should be continuity between the two thin wires.
All three behaved in this manner. Are you saying these are the culprit of the malfunctioning light, and if so where would one get replacement reed coils.
Doesn't look like a Radio Shack item, besides I avoid those stores at all cost.

I don't think you are going to find the tool at an automotive store as it is only available from the manufacturer of the connector and to the assembler of the harness . But I did find a sensor from Majestic Auto at the below site:

http://www.hondaautomotiveparts.com/auto/jsp/mws/prddisplay.jsp?inputstate=5&catcgry1=Accord&catcgry2=1986&catcgry3=4DR+DX&catcgry4=KA4AT&catcgry5=TAILLIGHT+%28%2786-%2787%29

So if you can go to a dealer, they can special order the part for you.

I'm still having problems with the exact wiring inside the module but the wiring diagrams for the 90-93 are very detailed and is what I am basing my understanding of the workings on.

mpumas
My sincerest gratitude for taking the time in helping and educating me.
I went to the Majestic Honda link you provided and ordered the sensor from there. The sensor was cheap at 14.66, but the shipping and handling added another 13.62, but no sales tax since I'm in NY and they're in Rhode Island.

I spent enough time working on this and don't wish to waste any more or driving to a dealer and ordering the part.

I strive to keep my equipment in good working order, I'm not fond of buthcher jobs, so actually it's a small price to pay if it makes me happy.

Once again, many thanks for all your assistance.