I've taken on the task to troubleshoot the Brake Bulb Safety indicator light which is always on. This is the 'Brake Bulb' light on the instrument panel, just below the door/trunk ajar indicators, and NOT the BRAKE light on top that indicates low fluid/e-brake. I have checked all 5 bulbs, and used an ohm meter to ensure I have continuity through all the bulbs at the left & right brake light sensor connector. I've gone as far as pulling out the dash instrument panel and the left & right rear brake light sensor units to access connectors and check for loose wires/connector problems (no problems). Finally, I cut to the chase by removing the cable from the (right) brake light sensor, then grounded the pin with the WHT-GRN wire at the Instrument Cluster connector (C4?). The Brake Bulb light still remains on after turning on the ignition switch (and not pressing the brake). I am using the electrical schematics from the 1990-1993 Haynes Repair Guide, and I've noticed some differences that are not mentioned anywhere else on the internet. But first:

My troubleshooting problem;
It seems like the instrument cluster has a problem, since grounding the pin at the instrument cluster (for the brake sensor circuit) is not making the light go off after turning on the ignition switch. (Normally, the left & right brake sensors should provide ground signal to the instrument cluster when the 5 bulbs are working correctly; I'm just bypassing all that)
Does anyone have a schematic of the instrument cluster itself? I figure I can try to re-solder a cold solder joint, but it would be nice to know where to aim instead of hitting every joint.


The other problem I experienced was with the Haynes schematics:
1. The left & right Brake Light Sensor Units (the ones attached to the tail light assemblies) and wiring are reversed from the Haynes schematic. In other words, on my 1993 LX 5 door wagon (KQ model) the sensor for the 3 bulbs is on the left (schematic shows right side), and 2 bulb sensor is on the right side (schematic shows left) The WHT-GRN wire that sends the ground signal to the dash when all bulbs are working properly comes from the Right side tail (schematic shows left) I've found a similar year (90-93) Sedan at the junk yard, and noticed the sedan car matches the Haynes schematic. Just thought I'd mention that as its a strange find... Unsure if the wagon is wired different, or if there was a change for the 1993 model vs the Haynes book)

2. Also seems to be different pin outs for the connectors into the instrument panel, as I was trying to trace the brake light sensor wire that goes to the Instrument panel. Book schematic says it is pin C4 (which I assume is the big 18 pin connector, pin 4). But the white/green wire I am tracing from the '3 bulb sensor' on the right rear is going to a different pin on the big C connector.

Can anyone confirm that this problem exists... and do you have the correct schematics or connector pin-out's for the 1993 LX Wagon?


FYI.. Ive had this car since 'birth' in 93, and its been exceptional all these years (and only 130k miles!!). Having this light on is more of an annoyance, and it just looked like a nice challenge to fix it myself

 

whoops...noob.. I should have posted this under Honda Accord (1990-2002). I re-posted there with a the fix for this problem (was a bad cap/solder joint) on the Instrument Panel