1994 Ranger brake light on. Here's the twist: car idling. if i unplug the connector from master cylinder reservoir, brake light goes out, though incident then press emergency brake on, brake light lights as it should.

Emergency brake off, light off. Plug connector back into reservoir - brake light on again.

is the switch in the reservoir the yellow float? Moving that up and down has no effect.

Jic you wonder. Reservoir connector in, brake light on. Press e brake, brake light gets a bit brighter. Release e brake brake light dims very slightly.

I hope someone has seen this one before. I sure appreciate any assistance.
john

 

Sounds like your reservoir is low on brake fluid.