Dead Battery, Aftermarket Radio, and a Whole Bunch of Problems

[dj_bosse]

So I recently got back from a vacation (~1 week of the truck sitting) and the battery on my 2006 Silverado 2500HD (6.0, ~51k miles) was completely dead - took it to Autozone to charge, put the battery back in the truck, and everything worked with the key on, engine off (all appropriate lights turned on, fuel pump primed, etc.). Tried to start the truck and it ran for about a half second and sputtered/died, almost like the fuel got cut off. At this time I noticed all the warning lights were on - ABS, SRS, fuel light, etc (none of which were on last time I drove the truck). The odometer also displayed "Reduced Engine Power." I grabbed my Autel scanner to see if there were actual codes being displayed or if the computer was just confused and there was no power to the OBD port. I was somewhat confused, so I turned the key off, took it out of the ignition, and opened the door when I noticed the radio didn't turn off (now I know what killed the battery!). I decided to start with the radio issue because it had the easiest solution - just put the OEM one back in. The aftermarket radio had been in for about a month without any issues. Pulled the radio and put the OEM one back in. Turned the key and the truck ran like it always did without any problems, without any lights, without any warnings. So I grabbed my Autel again (OBD port now has power) and ran full diagnostics on all modules, and it pulled a single code from just about every module - a U1000. The reader didn't describe the code but I assume it's just a dummy light saying communication failures. I saved the codes so I'd remember them, and then cleared them all to see if they came back. Re-ran the diagnostic and had no codes. Later in the day I drove the truck a few miles and there still weren't any codes.

 

So after the long backstory, I'm just confused on what would actually cause this to happen. Clearly it all stemmed from the aftermarket radio, but why would so many modules be affected by the radio? I had the base radio originally (no cassette deck, CD, AUX or anything), so I wouldn't have thought they'd run a bunch of stuff through the radio (like I know some Chevys run security systems through the radio which makes it a pain to swap them). I assume the power draw was there from the time the radio was installed until today, and it just wasn't noticeable because I was driving the truck enough to keep recharging the battery. I'd like to have a better radio in the truck but want to ensure this won't happen again. Luckily, all it cost me was 45 minutes waiting for the battery to charge and about 10 minutes swapping the radios and running diagnostics.

[davester]

The radio is still connected to the data bus the various systems use to pass data around.  From your description, it sounds like you used a wiring harness that at least supports RAP, which I believe uses that data bus, so perhaps your harness failed or was poorly made and screwed up that data bus from working.

[Formulabruce]

What I have found is that the factory "timer" in the radio, works with the dash cluster somehow, and all factory radios have it so they shut off in 10 min with key off ( but in) .

Messing with this timer can cause the problem you describe. I put a separate timed 12volt supply to mine after just using it in accy for a while.

 You should do the BCM ground wires on the rearward facing side of the DS cab support. These are usually corroded and need some cleaning and greasing for protection.