Have on 03 1500. W/ key off the brake lights do not come on. W/ key on they work but there is a small delay before they come on. Third light doesn't work at all.
I downloaded the wiring diagram but it wasn't any help. Any suggestions would be appreciated.

Phil

 

I am having the same issue...No brake lights with ignition turned off. However my 3rd brake light in cab is working ignition on or off.

I also cant shift out of park unless I disconnect the 2 wire connector on the shift cable at the column.

Any assistance would be greatly appreciated!

 

Sounds like a bad fuse maybe??

 

Success! After changing the the PCM (fuse/ relay box) to correct the "no park lamp" my brake lights stopped working and my shifter would not come out of park.

I went back and checked everything and found the Instrument Cluster-C2 connector (left side) was not seated completely. That's where the brake light switch signals run through.

Thanks to everyone for all the help!

 

maybe i'm about a month behind, but did anybody find a cure to this? my third light won't work at all, but there is about a three second delay in my brake lights.

 

Check your fuses

 

I've checked the fuses, but ALL are fine, wether they are for lights or the a/c or whatever.

 

figured out that the wire to the third brake light coming from the brake switch had been cut and used for the trailer brake controller. The last owner i guess didn't figure out that there was a pig tail for a brake controller in the glove box. as for anybody else with the same problem, check the switch, but don't remove it, because you will need to buy another, and check the CHMSL fuse.