Sounds like the solenoid mounted on the shifter. You have to replace the shifter to replace the solenoid. I would check the resistance of the solenoid. Usually 30 to 40 ohms. check the plug to it(Corrrosion) and the resistance of the wires from the brake switch to the solenoid(5 ohms or less). Those shifters are cheap. Could be the brake switch also. Next time it doesn't work, See if the brake lights come on.
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Sounds like the solenoid mounted on the shifter. You have to replace the shifter to replace the solenoid. I would check the resistance of the solenoid. Usually 30 to 40 ohms. check the plug to it(Corrrosion) and the resistance of the wires from the brake switch to the solenoid(5 ohms or less). Those shifters are cheap. Could be the brake switch also. Next time it doesn't work, See if the brake lights come on.