2012 5.0 rspec electrical issues

[Alr1999]

I’ve been having a lot of issues with my 2012 5.0 rspec. My alarm has been going off constantly, draining my brand new battery. My neighbor pulled a horn fuse hoping it would solve the problem. I got home from vacation over the weekend my car was dead so I jumped it. I tried taking over to get some gas and it wouldn’t turn all the way off. My engine turns off but not the computer. I’ve also noticed a lot of electrical issues like:
-Driver side mirror won’t shut when I lock it
-Rear passenger door sensor is reading open 24/7
-Rear driver side seat heater doesn’t work
-my fob isn’t working to lock or unlock
-stereo/aux works when it wants too
And a few other things as well
Has anyone experienced this?? I want to take it in but don’t wanna be charged an arm and a leg for some bs

 

[toxicavenger70]

When fully charged what is the volt your battery is putting out?

 

[Gunkk]

-Rear passenger door sensor is reading open 24/7

This alone will kill the car battery in less than 1 week.

Adjust or replace the failing/failed door switch. If the car has been in an accident, body panel fitment may need to be correct.


Background:

The anti-theft system sleeps when all doors/hood/trunk are closed (and tamper switches are "open" state, not conducting electricity). It arms automatically if the doors are locked with the fob and beeps the horn and flashes parking lights to confirm armed state if the fob lock is pressed twice.

If one of the door/hood/trunk switches fails to a "closed" state (which is the typical failure mode), it completes the anti-theft sensor circuit and wakes the anti-theft system, including possibly setting off the alarm if the circuit was previous in an "armed" state (i.e. if the switch has an intermittent failure).

If a switch is failed closed before the lock fob is pressed, the car will not respond with a armed-confirm honk/flash.

Even if the anti-theft system was never "armed" a failed switch (closed sensor circuit) will keep the anti-theft system awake 100% of the time until the car battery dies. This happens whether there are interior lights on or not.

This example is not related to the OP's problem, but illustrative nonetheless. There was originally an issue with the 2009 BH sedans whose hood tamper switch was activated by a rubber stopper mounted on the driver's side of the hood. The stopper was about 2-3mm too short and could fail to "arm" the anti-theft, keeping the system awake, and draining the battery. I got stranded at an airport once late at night because of it. There was a TSB campaign for free replacement to the larger bumper while under original 5/60 warranty.

 

[Gunkk]

-Driver side mirror won’t shut when I lock it
-Rear driver side seat heater doesn’t work
-my fob isn’t working to lock or unlock
-stereo/aux works when it wants too

Driver side mirror is most commonly a failed internal gear. If it makes motor and/or gear-grinding noise but doesn't move, the gear has failed. You or a competent mechanic can DIY the replacement in a couple hours (less than an hour with experience). There are threads on these forums with detailed walkthroughs, pics, part numbers, etc. The replacement gear can be had for $5-10 of Ebay IIRC. Dealers will charge typically $1000 (at least) to replace and paint the entire mirror. Most will not do the gear repair.

Rear seat heater if the 3 lights on button flash rapidly when pressed, the heater element module has failed. Replacement required. A competent automotive upholsterer can do this in an hour or two of labor.

Key fob not working for lock/unlock is most often the fob battery that will also manifest itself as "key not found" dash display when the fob battery goes completely dead. Less often this is a failure of one or more of the keyless entry antenna modules and/or the BCM, or related fuses & wiring. You can try checking fuses MODULE 2 and RF RECEIVER in the driver side instrument fuse panel, which you can see on the side of the dash when the drivers front door is open IIRC.

See also:

Hyundai Genesis (2012 - 2013) – fuse box diagram - Auto Genius

Hyundai Genesis (2012 - 2013) – fuse box diagram

www.autogenius.info

stereo/aux works when it wants too is a bit vague. The AUX audio input is a non-standard 3.5 jack. Normal male-male 3.5 stereo headphone wires will not work, or if they do will limit audio to once side, or weak mono. If the entire head unit has intermittent failure (screen goes dark), there's a bunch of things you will want to check, almost all of it wiring. If the audio amplifier cuts out periodically, that's a false-positive short error on POST in the amplifier that can be reset by pulling the negative battery cable for 30 minutes, or by letting the car sit for a couple hours until the amp capacitors drain while key off.

There are bluetooth adapters available for relatively cheap that work well. I use one of these, and the aux jack is designed for the car and works well enough for $37. It takes its power from the USB port so no batteries required.

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