08 silverado marker light ALWAYS on

[alitterit]

Got a new truck so this truck has been sitting a little lately, went to start it to mow and the battery was dead which was weird but figured maybe left something on. As soon as I hooked up the jumper cables I noticed that the front pass side marker lights came on and only those lights (both bulbs, ignition was off). I found its the blue wire with white tracer that is supplying power which if I followed it correctly went back to the fuse box under the hood, after pulling any and all fuse labeled lights with no success I pulled every blade fuse 1 by 1 and the lights never went out. So I'm thinking I either A) followed the wrong wire or B) need to start tearing into the wiring harness and find out whats going on where because something is back feeding. 

 

Has anyone had any issues like this before? Did a quick search and any lighting issues I found were dash/ interior related or turn signal so really weren't a help. Hoping to get some kind of insight before I just tear into this to help save some time/ effort haha. Luckily this trucks just a backup so down time isn't an issue. Plus side forces my GF to get her stuff out of the garage so I can get the truck in there to work on it at night/ rainy days haha...   TIA 

 

Also truck is an 08 Silverado with all stock lighting. 

[no HD]

With all the rain we've been having (at least here anyway) and the truck sitting, could water have leaked in somewhere and maybe got to the bcm or something. Maybe if you ever get it into the garage and it has a chance to dry out it might cure itself. My F-550 the radio would come on whenever the bcm got wet. With 2 batteries it never caused a problem and I would turn off the radio when I parked the truck if I thought about it. 

[alitterit]

We have been having a lot of rain here too, (Philly area) but the spot the truck has been sitting is only a few feet farther back then where it gets parked when I was still driving it anyways so doubt thats the issue. I mean moisture could have made its way in there and not dried out since the engine hasn't ran and created any heat but at the same time its been fairly warm still so I don't know. Maybe Ill pull the BCM and bring it inside for a a day or 2 and also make sure no water is in the connections and see if that helps any. Just weird this problem came out of the blue, few weeks ago when I drove this truck it was fine now all the sudden BOOM electrical gremlin LOL. 

[alitterit]

Another thing does anyone know if the BCM from an LTZ is the same for an LT? I have the LT but have a buddy with an LTZ and if so I'm sure he would be willing to stop by so I can swap his over to my truck or visa vera to see if that solves my issue. I know the LTZ trucks were better optioned so not sure what differences there may be in the BCM that control those options. TIA... 

[Black02Silverado]

13 hours ago, alitterit said:

Another thing does anyone know if the BCM from an LTZ is the same for an LT? I have the LT but have a buddy with an LTZ and if so I'm sure he would be willing to stop by so I can swap his over to my truck or visa vera to see if that solves my issue. I know the LTZ trucks were better optioned so not sure what differences there may be in the BCM that control those options. TIA... 

It will not work, they are linked by the vehicles VIN.