LED 3rd Brake Light is Dim on a 1997 Chevy 3500 Series Truck

Question:

I have 97 Chevy crew cab 3500 6.5 auto.recently added sleeper cab to it,it comes with led 3rd brake light,finding the wire yellow I believe and black ground I used test light,its very dim,cargo light wire bright and other wire bright,upon applying brake pedal yellow activates but dim,bad wire connection switch,where does it originate,help

asked by: Keith

Expert Reply:

The third brake light circuit on your 1997 Chevy 3500 uses the CHMSL circuit (center high mount stop lamp). If it is working then the circuit is fine but if you are having dimming problems then it is likely a poor ground connection.

Ground problems normally show up when there is more draw on a system such as when you have the running lights on and then use another function like a turn signal or brake light. Make sure the grounds are attached to clean and corrosion free bare metal surfaces.

expert reply by: Michael H