Had an unusual brake issue on my 2003 Dodge Ram 1500 Hemi with ABS that I cannot find described anywhere else. Twice in last 6 months I've had the brakes fail to respond (no stopping power at all, no brake lights coming on) but both times I've had full pressure at the pedal. First time was doing about 10mph on a slightly icy level road in stop and go traffic. Applied brakes, had pressure, no stopping. Wasn't sliding on ice, brakes never locked up. Pumped the brakes and brakes eventually slowed vehicle. Almost nailed the car in front of me. Jumped out and asked the guy behind me, said he never saw brake lights come on. Had dealership look at brakes, they test drove and inspected, said everything looked fine and the didn't notice any braking problem. Thought it might have been all in my head at that point.
Last weekend it finally happened again. I was going down a steep hill starting from a complete stop. Got up to around 20mph, hit the brakes, had pressure at the pedal but the brakes did not slow the truck. Didn't even feel like they were applied at all. Pumped the brakes and still no response. Got to sharp corner in the road at bottom of the hill and pumped once again and eventually stood on the pedal. Crashed through guard rail and came to gentle stop in small brook. The Ram took that punishment fairly well :-).
Had a friend following me that day, said my brake lights worked fine for the 10 mile ride until the top of the hill and he never saw them come on after that. No skid marks on the road either (dry conditions that day).
Dealership is again failing to find a problem. I've talked to a mechanic friend who suggested possibly internal seals on ABS system failing and plugging system (once pressure is released, seal returns to normal, and waits silently for it's next attempt on my life). Been researching the hell out of this, but run into so many posts about brake failure due to no pressure that its hard to find answers. Figured I'd just come to the experts.
Sorry for the ridiculously long first post and thank you all for any help!

 

Brake Light switch is on the pedal itself. So if your brake pedal is moving your lights will work.

As for no brakes when you press on the pedal. Have you ever flushed the fluid?

 

The electrical side of the brake lights has nothing to do with the mechanical side of them working.

However, with ZERO brakes, I would look at the master cylinder and/or vacuum booster. Flushing the lines is easy and cheap. I recently did mine in less than 20mins by myself and with 2 qrts of fluid.

 

Thanks for tips. Mechanic eventually found binding in the brake pedal assembly itself after numerous attempts at depressing the pedal. When he used the electric pedal adjustment switch to move the pedals slightly closer he was able to cause complete binding on almost every attempt. Would've helped if I didn't use the phrase "had pressure at the pedal" when I really meant had way too much pressure and couldn't really depress pedal. Thanks again for trying to help. This forum is the best!

 

I'll take non-moving parts whenever possible please! Good to hear you figured it out before it was too late.