I had an interesting failure with the front brake light switch and I wanted to pass it along. On the way home a few days ago I discovered the brake lights would not come on when the front brakes were applied. The rear brake pedal activated the lights correctly. A faulty brake switch was confirmed by disconnecting the spade terminals and directly shorting the wiring connectors. I removed the switch and tested it with a meter. It was indicating 50 to 55 ohms resistance when the contacts were in the open state (little button pushed in). In the closed position, button out, resistance was zero, as expected. There must have been some corrosion in there that was causing the switch to not work correctly. So how do you get corrosion out of the inside of the sealed up switch housing? There are two little partially open-to-the-environment openings on the bottom of the housing and I squirted some chrome wheel cleaner into one of the openings. I figured the same chemical action that takes oxidation off from chrome wheels would work to dissolve the corrosion inside the housing. I let the chemical action boil out the corrosion for a few minutes while shaking and cycling the contacts. I used water to thoroughly rinse out the switch followed by compressed air and Deoxit contact cleaner. Now there is no resistance indicated when the contacts are in their open state. I put the switch back on and all is well.
I?m still going to replace the switch. Who knows the condition of the springs inside the little housing. I?ll bet they are corroded and may fail anyway. At least it?s working now.
I?m still going to replace the switch. Who knows the condition of the springs inside the little housing. I?ll bet they are corroded and may fail anyway. At least it?s working now.