I own a 1998 Chevy K1500 Silverado. About a year and a half ago my interior lights stopped turning off. I found that the only way to make the lights go out is to pull the interior light fuse. With the fuse pulled my lights will go out when the key is in the off position. With the key in any position besides off and the radio on my cab lights are on half bright. If I turn off the radio or pull the radio fuse the lights go out. My mechanic and I both investigated this and came up with the same answer: the Keyless Entry Module. After living with no cab lights for a year and a half (in northern New Hampshire) I broke down and paid the 180 bucks for the “Remote Function Actuation Module” (I had to take my dash apart and get the part number off the old module to figure out which one of three or four possible modules was used in my truck). Now that I have replaced the module I still have the same problem. If it’s not the module then what is causing my lights to stay on all the time with the fuse in or come on half bright with the fuse pulled?
My guess? A short to ground that’s completing the circiot for that lighting module.