is it that the red light just stays on

[normren]

The red brake light on the dash is on and I don't know why or what i should do to figure out what's wrong or how to turn the light out .

 

[KC87]

If y'all haven't done anything to let air into the system perhaps the emergency brake pedal isn't coming up all the way

 

[TurboTGuy]

Does the pedal feel stiff? Might be the accumulator ball has gone bad. Not a situation you want to be in when trying to come to a stop in traffic.

 

[pacecarta]

three things can turn brake light on
it turns on when the wires for the system get grounded
if you still have power master ..unplug the pressure switch and turn key on , if lamp is still on its not the powermaster
then check the park brake pedal , theres a popper switch under dash above the pedal by the firewall with a single wire spade connector , it could be stuck
if you unplug it and light stays on the one thing left is the switch at the prop valve on frame under drivers feet
if you unplug it and light goes out thats the problem , it activates if the brake line pressure front to rear is out of balance like when a wheel cylinder pops or a line breaks or if theres air in lines or mastercylinder is defective internally leaking front or rear

then theres another cause thats outside the norm and caused by monkeying around
if theres an electrical issue causing one of the wires to PM , prop or park brake to contact metal and get a ground
or someone has been monkeying around with the gauge cluster and damaged the circuit film on back of cluster causing a short to that indicator bulb
or if someone did some stupid electrical work and tapped the line