2005 1500 Silverado 5.3L w/ 118k that after a several days, my battery goes dead. I put in a new battery Oct 1, 2020, and it sat for most of November and December. Prior to November, I drove this truck almost daily. Had to jump it to start it. Took it to AutoZone and they put in a new battery. Drove home and after not starting it for 4 days, battery dead again. Took battery out and charged battery for 24 hours, battery read 13.2V, put back in truck locked truck, amp meter initially reading 2+A draw. After I waited 30 minutes, the draw down to .05A. All good. Left alarm on, hood unlatched. Day 2, 12.84V, Day 3 12.82V, Day 4 12.42V, and .3A draw, Day 5 12.12V. I'm losing battery power. Started truck to for short drive, after 10 minutes I notice Oil Gauge is reading 80 pounds of pressure. Don't recall oil pressure previously. Are these two items related, or do I have two problems, Parasitic Draw and Oil pressure problem? I hear that instrument cluster is a know problem for this vintage truck. How can I confirm it's bad, if so, who rebuilds these, and what about oil pressure. How do I diagnose and what's next steps? This is my first time on this forum, so thanks for all your help.

 

The oil pressure transducer/sender is probably the culprit reading 80, easy fix although you have to get on top of the engine towards the back to replace.

 

So, will / can a bad sender actually create a power draw from the battery with the ignition off, keys out and alarm set?

 

I don't know, I was addressing the suspect issue with the oil pressure.

 

0.3A is a too much standby current.
When you see that, start unplugging fuses until it drops.

Check the ground connection on the oil pressure sensor.

 

Posted By: EMitiska
So, will / can a bad sender actually create a power draw from the battery with the ignition off, keys out and alarm set?
As in previous post about the current draw, yes it is way high. You posted with alarm set, my suggestion if possible is to not set the alarm as that my be were the problem is.

 

Here is GM's process for parasitic drain.

https://gm-techlink.com/?p=14171

 

There isn't much there to help. I have the same issue with a 2004 Silverado that is intermittent. Works fine for a month then it goes dead again. Most of the time I know it is coming because the digital display shows Chinese characters after I shut off the engine and remove the key. I can disconnect the battery, hook it back up, and everything is fine for a while. I pulled a bunch of fuses but the dash never powered down.

 

Side note: I noticed it tends to happen when a front tire is low or parked at an angle. Not sure if this 2004 model has low pressure warning or not. Thought maybe the ECM was going wacky when a low pressure warning was sent.

 

If it had the tpms it would tell you if you had a low pressure.