2017 Silverado battery drain from fuse 39

Jason Redditt · January 18, 2022

I have had my son's truck at the shop for over a week and they are having a hard time finding out what is draining the battery. It's a new battery. There is a very very soft high pitch noise you can hear from the wheel wells and under the truck that will shut off when I turn the light switch all the way to the left but will come back on after some time. I can also make the noise stop and the battery won't drain over night if I pull the #39 fuse from under the hood that is labeled IGN/MISC. So far the mechanic can figure it out. I looked up the wiring and attached the screen shots. Could it be the Multifunction Led Control module?

swathdiver · January 18, 2022

1 hour ago, Jason Redditt said:

I have had my son's truck at the shop for over a week and they are having a hard time finding out what is draining the battery. It's a new battery. There is a very very soft high pitch noise you can hear from the wheel wells and under the truck that will shut off when I turn the light switch all the way to the left but will come back on after some time. I can also make the noise stop and the battery won't drain over night if I pull the #39 fuse from under the hood that is labeled IGN/MISC. So far the mechanic can figure it out. I looked up the wiring and attached the screen shots. Could it be the Multifunction Led Control module?

My eyes won't allow me to read the chart. Did the mechanic use his scan tool to do a parasitic draw test? Should be easy peasy to find with the right tools. If this truck is a keeper, consider getting an MDI2 with GDS2 software on a laptop.

Jason Redditt · January 20, 2022

On 1/18/2022 at 4:58 PM, swathdiver said:

My eyes won't allow me to read the chart. Did the mechanic use his scan tool to do a parasitic draw test? Should be easy peasy to find with the right tools. If this truck is a keeper, consider getting an MDI2 with GDS2 software on a laptop.