Over the past weekend I acquired my late grandfather's 2003 sierra with the 5.3l. This truck only has 44,000 miles on it and ever since his passing in has sat around and now has has a pretty bad electrical issue. Everything I want to start the truck I have to jump it because the battery gets completely drained. Once it's running after being jump the instrument cluster takes about 5 mins to turn on. I've hooked a computer up to the obd and the pcm is giving out all the information but the cluster is getting power. I'm have a feeling that it's the bcm not going to sleep or is faulty and is draining the battery. If anyone has any insight or has had similar issues let me know.
Over the past weekend I acquired my late grandfather's 2003 sierra with the 5.3l. This truck only has 44,000 miles on it and ever since his passing in has sat around and now has has a pretty bad electrical issue. Everything I want to start the truck I have to jump it because the battery gets completely drained. Once it's running after being jump the instrument cluster takes about 5 mins to turn on. I've hooked a computer up to the obd and the pcm is giving out all the information but the cluster is getting power. I'm have a feeling that it's the bcm not going to sleep or is faulty and is draining the battery. If anyone has any insight or has had similar issues let me know.