Honda brake lights - Mike Jacobs
I would welcome some assistance to help solve the brake light problem on my honda. The dashboard is fitted with a safety indicator which informs the driver if a door is not closed properly or a brakelight bulb has burned out etc. Each side at the rear has a brakelight sensor unit fitted in series with the brakelight circuit. Safety indicator lights up at regular intervals to warn me of bulb failure but if the offending bulb is tapped it lights up.(I know this as I have wedged something against the brake pedal to hold it down. I am sure the trouble is NOT loose bulb connectors, as different bulbs are affected.Besides,the tail lights aren't affected,(sharing the same bulbs)and have cleaned up all the connections. The springs pushing the terminals against the bulbs are all in good condition.The bulb will then stay on again after it has been tapped but the safety indicator with it's accompanying dashboard warning light comes on a bit later and stays on but the bulb doesn't seem to be blown. Could it be a poor earth? The safety unit must be detecting a change in resistance somewhere. I am an experienced multimeter user but don't understand the Honda Manual testing procedure. Cheers, Mike.
Re: Honda brake lights - Andrew Hamilton
Although you have cleaned brake light you may not have completely removed all oxide. I use metal polish and finish with a spray of WD40 on bulb and its socket. Alternatively the bulb contacts being soft solder may have dented to prevent good contact. Also the bayonet pins may be distorted or the socket distorted so vibration increases contact resistance. Finally the bulb may be faulty internally.

Checking the circuit resistance is easy with a multimeter but may not be accurate at the 5amps used by each bulb. I would measure the voltage drop from battery +ve terminal to bulb and bulb to battery -ve terminal. Don't forget when putting pressure on the bulb you are distorting the socket and any circuit board. There could be a hairline crack if you have any printed circuit connections.

Do let me know what the cause is!
Re: Honda brake lights - peter
I am glad I dont drive behind you regularly- 60W Brake Lights?
Re: Honda brake lights - Andrew Hamilton
OK, Ok 25W for brake element and 5W for rear light. Equivalent to maximum total 50W for two brake lamps or 4A. The meter resistance would prevent an accurate measurement of normal current.
Re: Honda brake lights - Mike Jacobs
Thanks Andrew, will get back to you once I've got my head around it! Mike
Re: Honda brake lights - Mike Jacobs
Andrew,I think you may well be right. I used brasso to clean the socket contacts and emery,brasso,WD40 for the bayonets. All the rain we've had flooded the rear lights. Took ages to clean everything. Bayonets slightly ovalised. There is one slightly dodgy light (double lights each side) but the above has improved things no end.I think we've cracked it.The contacts were indeed oxidised. Now the warning light keeps off. There's one socket that needs a bit more attention. Stanley is a good guy! He makes good lights.(Stanley in case you don't know it,is theJap manufacturer of light units) It is surprising how hot a 21watt bulb gets. I mean deadly hot. Many thanks for your help. Cheers, Mike.

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