Found out one day the 1999 Blazer im working on was dead, sure enough, i found it was shorting out some where and killing the battery. Put a test light in line of the negative cable and the light goes on like it should for battery drain indication, but after a few, the test light starts flashing. Open the door and hear the TCCM clicking away. So I unplugged the TCCM, the dash switch, hell I unplugged everything including the tranfer case wires, and still the blinking test light. The test light is on all the time, but the light pulsates likes its connected to a relay. So by pulling fuses one by one, I noticed that when I pull the TBC fuse the light goes from pulsating to an actual brighter blink, and then to kill that I remove the 50amp main body fuse, but obviously thats not it. I am at a total loss here, what the hell is causing a blink, there are no breakers left. Any help with this would be great............Thanks

 

TBC == Truck Body Control - aka. Body Control module. The TBC fuse powers the Body Control Module (BCM), Remote Control Door Lock Receiver, and Multifunction Switch Flash to Pass featuer all on CKT 1140 (circuit 1140).

Have you measured the amp draw on the circuit? Does the blinking persist if you test at the TBC fuse instead of at the battery? How about when you disconnect the BCM or RKE module? The BCM is located just right of center under the dash. It will have 3 connectors plugged into the left side of the module.

I did a search for 'TBC' and 'swartlkk' as the author and came up with THIS THREAD and THIS THREAD which doesn't precisely match your problem, but could provide useful information.

 

No way to measure voltage at moment, should I look into the bcm as a probable cause of the drain?