[SOLVED] Intermittent Power Cycling of Cabin Electronics + More

Year/Make/Model: 2011 Mazdaspeed3 Base
Mileage: ~128,900
Location: Indianapolis, IN

Concern: Issue began as radio instantaneously power cycling/resetting for seemingly no reason while driving around. Has since progressed to sometimes prolonged headlight flickering, loss of electronic power steering, handbrake light on while handbrake is lowered, throttle being extremely sensitive/bucking at constant throttle pedal input, and constant/repeated radio resetting. There was one instance where everything but the power steering reset back to normal for the remainder of the drive, and I was on only hydraulic PS until I got to my destination.

When headlights are flickering, they are still on, just flickering between full brightness and dim. Radio resetting is like if a button was pressed for an instant reboot, there is a snap sound like an audio cable being unplugged from an amp and then the welcome message plays on the dash immediately.

DTC's: None

Modifications: only electrical modifications are Sealight LED headlights and high beams with adapter pigtails to the halogens - installed for almost 2 years with no issues, and mishimoto LED fog lights - installed for a little over 1 year

ECU/Tuning Software: Accessport/Accesstuner
Tuner: Freektune
Is the concern intermittent? Yes

Can you duplicate the concern? Yes, but not every drive or every time executing something that has triggered it.
Things that have caused the issue:
- turning steering wheel
- using turn signal
- pressing brake pedal
- pressing clutch pedal
- raising handbrake
- lowering handbrake (as seen in log)

Log: I had never been able to capture issue in a log due to how abruptly and sporadically it occurs, but today I was taking datalogs with the car still and battery voltage on my accessport screen to test different things that have triggered it to see if it could be replicated. Luckily, I managed to catch it in a log, and what triggered it was lowering the handbrake.

Recent repairs/troubleshooting: After the incident which knocked out the power steering, I took a peek at the battery terminals and cleared a little ring of blue corrosion off of the bottom of the positive terminal and also hit the strut tower ground with a wire brush. The car drove perfectly after relearning trims for a couple days until the issue resurfaced again, but in its originally minor state of just resetting the radio.

Comments: I will be getting a new battery somewhat soon to see if that is the source of the issue as it seems like that would be a good place to start. That being said, the warm idle is right around 14.2 volts and the car cold starts on 2-3 cranks every time, even in <20F cold. What is very strange to me is that while sometimes the steering (typically large voltage drop when wheel is first turned) causes the issue, it seems to be caused as well by really minor things like using the turn signal or lowering the handbrake. From what I can gather, the issue is triggered by an instantaneous steep voltage drop, like down below 10.5 volts from 13-14. Normally, lowering the handbrake and using the turn signal cause a drop of ~0.3 volts.

Wondering if anyone has seen anything remotely similar to this as I have not been able to really find anything else about similar symptoms elsewhere.

 

14.2v idle should be charging just fine. could just be a dead battery time for a change I know these cars get weird when it's time for a battery change. how old is the battery?

 

At least five years old, I haven’t changed the battery since I got it because I never had any issues with starting or running until now. Could just be time for a new one

 

I lean battery myself. Second bet would be chassis grounds

My car had a battery that seemed fine held voltage started the car fine etc but sometimes the car acted just weird. Lights dimming when turning the wheel was one of the symptoms. If the fan was all the way up you could hear it slow down too

 

Replaced battery last Tuesday and issue has not happened since. Probably was the issue because I discovered that the old battery was from December of 2017. Can mark this as solved now with the cause being battery on its way out.