The mechanical switch that actuates the brake lights on my 93 Ford Ranger doesn't work until the brake pedal is pushed down almost to a lockup position. I've tried a new switch, and I even tried to shim it to get the thing to work at a light pedal. Needless to say, in traffic where a light pedal is often all you need to slow, the driver behind needs to know you are on the brakes. That isn't happening. Any suggestions? Thanks.