markm1993

I've taken on the task to troubleshoot & resolve a problem where my Brake Bulb Safety indicator light on the Instrument panel which is always on. This is the 'Brake Bulb' light just below the door/trunk ajar indicators, and NOT the BRAKE light on top that indicates low fluid/e-brake. I checked that all 5 bulbs were good, and the WHT-GRN wire from the right taillight bulb sensor circuit connector (PIN 1) is correctly grounding the wire that leads to the instrument panel (connector pin C4 on circuit board) Even grounding the C4 pin into the dashboard would not make the bulb extinguish. I removed and opened the Instrument panel, and after creating my own schematic of the door/brake bulb area, I found the problem. FYI I am using the electrical schematics from the 1990-1993 Haynes Repair Guide, which has the brake light sensor's revered in the schematic.

Problem was a capacitor that leaked, and corroded a 1/2" square area on the instrument panel circuit board. After cleaning it up and re-soldering the capacitor connections... it works! I'll be replacing those caps now, since they'll likely fail soon. (UPDATE: I replace the 4 capacitors in that area, and its all working good)


Regarding the Haynes 1990-1993 manual, the schematics are good except the left & right bulb sensor circuits & wiring are reversed in the Haynes schematic, too. The *may* only be a problem for the 1993 Wagon, or possibly all 1993's are wired reverse of earlier year models? For this 1993 wagon, the one marked Left in the schematic is actually on the Right, and visa-versa. It's the sensor circuit on the right has the WHT-GRN wire on Pin 1 that goes to the dashboard. It should provide Ground to the dash when all 5 stop bulbs are working good.

Lastly, I reverse engineered a schematic diagram of the door open/Brake Bulb circuitry. If you want a copy, let me know

brakedrum

This is a post I'm sorry I missed. I have the exact same thing going on with my instrument cluster. markm1993, in case you stop back by here, I would love to learn more about how you repaired your cluster. My cluster has the same corroded section, but I don't know how to clean it up. Replacing the leaky capacitor (what to buy) etc., is also info I need. Anyway, with any luck, perhaps you will log back in. Thanks.

markm1993

Self made 1993 Accord wagon dash board schematic. Includes the capacitors I replaced to fix the Brake warning light problem

markm1993

Oh, questions came to me regarding how to identify the bad capacitors. First, the circuit board looked burnt in the area of the bad cap(s). It was actually a chemical burn, and not from heat/fire. My friend has this impeccable talent where he can smell a bad cap. He says there is a distinct odor when a cap goes bad...like bad socks. IDK, I couldn't tell, but he nailed it. I replaced all the caps in the area anyway, because its easy and cheap, considering the labor to remove the dashboard again. .I hope you are successful as I was with this, if you try it. What you got to lose, anyway?

FYI.. the schematic is my own reverse engineering of the power supply section of the board, and not from any 'reliable' source. I think its as good as it can get, but there could be flaws or other things I missed. Be sure to check the circuit board to match the "C" identifiers, and make sure you match the cap specs as you remove them. You MUST match the farad rating, and generally its ok to go with a higher voltage rating if you cant exactly match the original part. AND... dont forget to also match the cap's polarity!

brakedrum

Thanks for your reply! Yes, my printed circuit board is burned/stained like that, and when it burned, I smelled that distinct smell you mentioned. I knew it was trouble, and sure enough, the temperature gauge died, and the SRS light stays on all the tome. The brake lamp warning still comes on and off, and all of the door ajar indicators glow on damp or rainy nights.

Last year, I got another cluster from an ebay seller, but never got to install it. I don't know if it works. It happens to have a similar burned spot on it, so it probably has things wrong too.

Thanks for the specs and tips, but I won't be able to do the job myself. I hope to let an electrical engineer have a look at it.

Are you able to post the sheet you made, and perhaps point out the capacitors involved?