So on my 04 my brake lights will start flashing on and off when the truck is parked, may do it while I'm driving but I don't know. This has been going on for a while but the last two nights it's drained my battery down and needed to be jumped. My trailer controller will flash "O.C." on and off also. Not sure if the two are related because one happens without the other and sometimes at the same time. Any ideas what's causing this?

Also, the first time I jumped the truck off it stared idling extremely rough. Fluctuating from 500-900 RPM for several minutes, the second time, today, it didn't do that. I figure it's just the computer resetting itself, but seemed to last longer than expected.

 

Thinking about disconnecting my trailer brake control to see if it helps. Anyone know how?

 

Just wondering if you found out how to fix this. Did the trailer controller have anything to do with the lights turning on?

 

Yeah I disconnected the trailer controls and it stopped. Plugged it back in one day to pull a trailer and it started up again. I don't know why it causes it but when it's unplugged everything is normal.

 

My old silverado did the same thing, never did it enough to drain the battery but it was really annoying, ended up pulling a bunch of aftermarket **** out from under the dash that the previous owner had installed (car alarm, hands free cell phone package, and some other small ****)