body control module

[caseyj]

Hello im new to this forum,,,i have a 99 gmc sierra that im having probs with. My headlights , daytime running lights , dome lights, door unlocks all went out at same time. At same time "security" flashed on display.
I looked and found only fuse blown was "tbc" in the engine compartment fuse panel. When i replaced the fuse it emmediatly blew, replaced again ,,blew again,,replaced with a 15 amp fuse then(supposed to be a 10 amp, it was cold and i been working for 12 hours straight) headlights came on . i got into truck and smelled a electrical burning smell,,,,pulled the fuse,,,tried to find where smell was coming from, msut have had a wire rub under dash cause i grabbed a 10 amp from fog lamps and put in,,,,everything works ...........until i turned my truck off. lights stay on. So i pulled and tested the relays for the headlamps,,,all good,,ne way. if i turn my truck off with fuse in then remove after truck is off,,,truck immediatly dies after starting,,if i pull fuse (tbc underhood electrical compartment) before i shut my truck off ,,truck starts up fine next time. I've done some looking into schematics on wiring and think my body control module is fried out,,,,i was told its in my center console but where is my center console. behind the radio or what. Does ne one have ideas if it might be something else besides the bcm. Also if i do find the bcm is there a way for me to check it?

[caseyj]

oh btw it is the new body style.......

[sully16]

I have a very similar problem with my 99 Z71 ext cab. I had an amperage drain that would drain my battery overnight. Every morning I would have to boost my truck to start it for about 2 weeks until I finally found the drain. It was the radio circuit in the underhood electrical fuse box, but wait it wasn't the radio that was doing it. There is another line that draws power from this fuse, as near as I can figure it is something into the BCM that controls my dash warning lights. What I did is run the draining line to my other battery (my truck has a second battery). I thought that I had temporarily fixed my problem but then when I went to start the truck I turned the key and the 'SECURITY' light flashed and now I have no power locks or power mirrors as well as my radio now shuts off with the key where as before it would stay on until the door was opened. I to believe that my problem is the BCM which by the way to answer your question is located between your knees behind the cover panel. It is very easy to get at by taking out the few screws from this kick cover panel and you will see the BCM it is a black box about 4" x 4" x 1" thick with 3 electrical harnesses plugged into it. I already took mine out and put it back in to try and maybe reset it, but no luck. From what I have read so far I will have to take my truck to the dealer and have him re-program the BCM. Unless someone out there knows how I can do it myself manually that would be great. I have an OBDII handheld reader but it only resets PCM codes and cannot read the BCM codes.