Parasitic draw coming from radio fuse that's killing my new battery in 2-3 days.. Tracked it to that fuse. It has the factory headunit that hasn't been messed with. Anyone else ever come across an electrical issue like this? And what could resolve it?

 

The radio is always powered or there would be no memory. Probaly not the trouble.
Is anything plugged into the auxiliary 12 volt plugs? Or any other after market things? Any CheckEngineLight ? Brake lights stuck on?

 

No accessories plugged in. All doors shut. Only check engine light is Abs light on due to faulty sensor in wheel hub needing new wheel bearing. My ohm reader reads 1.5+ amp draw on battery with everything off. When I pull the radio fuse it drops to under 50 milliamps.

 

I was told to check the RAP relay or possibly reprogram key fobs

 

Do you have, or has there ever been, a trailer hitch on the car?

 

No trailer hitch. If I pull the radio fuse the drain goes away. The radio is the original factory one that's never been removed from the dash. No aftermarket add ons anywhere on the vehicles electrical system..

 

If you unplug the radio itself does the drain go away?

 

There are other things that use that fuse. Maybe the RCDLR?

 

His bio shows the car is a 2008 model. Since that year had the known issue dealing with power loss affecting the programming , I would be careful about disconnecting any power wires while diagnosing.
Also which radio ? Regular or the upgraded one with the separate amp ?

 

What year is the car? Which radio?
Does the fob work as expected? Does the TPMS work? Is Onstar, XM/Sirius in the car, activated or not? Do you have the "Premium" radio with sub woofer and amp, steering wheel controls
Which fuse are you calling the "radio fuse"? Has ANY work been done before this started?

If the RAP relay was stuck you would be able to operate the windows when you first enter the car. If the RCDLR was involved the TPMS and fob would not work correctly, it is always hot on the same fuse as the radio.

What is the full code causing the CEL? One of them means "short to voltage".

The RDO fuse is always hot, the radio is turned on/off by a digital signal from the BCM, not the RAP relay.

Have you made sure that the dimmer wheel is not ON? Not all years have that.

Are all of the door switches operating correctly? Including the lift gate? Is there a fuse in position #11 under hood?