Been having some funky electrical issues and looking for some advice where to start troubleshooting.

Obviously have a short somewhere. Maybe once every month or two I'll return to my car after work (or in the middle of the night ) and it will be honking, flashing interior dash lights (signals, security, etc.) ~ once per second. Battery will be dead and won't start, doors won't unlock etc. Boost it, and it runs fine. It'll then be fine again for a few weeks until randomly occurring again.

I assume it's related as they started around the same time - once in a while when I shut the car off the lights won't automatically turn off after the 30sec or so. Even if I double click the lock to turn off immediately they stay on and I'll have to go turn off at the column. Again - totally random.

The dead battery issue seems to like wet weather (snowed yesterday). The headlight one is random.

Battery reads 13.3V running / 12.2 volts off (after running headlights and blower for a minute after shutting off). Parasitic draw off the battery is minimal. If I could predict when the problem would arise I'd start pulling fuses, but it's totally random and I usually don't have a multimeter on me.

Looking for some advice from the more electrically inclined - where to start looking? I'm thinking from the headlight/fog lights and moving back as those would be the most likely to get wet.

first step - what aftermarket electronics do you have installed on your rig? have you removed ALL of them to rule them out? aftermarket remote start/alarm installed?

Pulled the remote start module after the first occurrence. Have a Redarc TowPro controller in there so I guess I should unplug that as well. Unplugged the cigarette lighter USB adapter last night. Nothing else.

First thing is get your battery load tested....what is your parasitic draw and what is minimum to you ??...draw is usually the Reserve Capacity of the battery divided by 4...100 minute RC is 25 milliamps...pulling fuses is NOT the proper way to perform a parasitic drain....voltage drop testing is...a "short" is a term many DIY'ers throw out there...a short will either blow a fuse or melt some wiring...if it is a draw an intermittent it will be hard to locate...I use advanced test equipment like a labscope and can monitor a drain for hours to see when it happens and can set an alarm so I can test...my advice is find an auto electric shop in your area.

might as well pull the redarc. did you install the plug and play one directly into factory harness? I have the tow pro elite and installed via the plug and play connector to factory plug. I haven't had any issues with it in years since the install. the drain is very very small. unless it is malfunctioning but worth a check. when you press the dial with no trailer does it light up blue and then fade?

Have the battery load tested as suggested, 12.2 is a little low, should be around 12.6 AND have the alternator tested as well, it should be 14+ volts while running, 13.3 volts is too low while running, this could be a bad battery and or alternator!

It wouldn't hurt to check/clean all connections, especially the grounds!

Low voltage and or bad connections can do some crazy stuff!

How do you perform voltage drop testing to identify a drain? I remove the negative cable from the battery and insert the meter (set to amps/milliamps) by connecting one lead to the negative battery terminal and the other to the negative cable.

Do you have an aftermarket roof rack? If you do, look at the connectors behind the kick panels. Both driver and passenger. May have a water leak at the bolts, working it's way down into those connectors. Fuzzy green or blue shit in the connectors, which is corrosion, will cause crazy issues. Especially if it rains, like you stated. Good luck.

Draw is 8.5-11mA after having sat for a day - by your rule of thumb my battery should be 28.75 (115min RC/4). I don't necessarily mean a short to ground but there's definitely something shorting a switch or relay somewhere that would cause an accessory to stay energized when it shouldn't. The lights staying on after double clicking the lock is a red flag to me but nothing concrete.

I'll get the battery tested. After running it yesterday it's sitting at 12.6V off/14.1V running so my original numbers might have been coming off that hard drain when it died, but getting it tested is an easy check.

I've wheeled the truck a lot and did a good blast of the drivers kickpanel connections a while back but will do it again. Does anyone happen to know for a 2012 which connectors are related to headlights? I miss the old days you could get a FSM/Electrical Manual without having to have access to the Toyota TIS or whatever is it now.

Anyone able to ID this connector and specifically the grey wire? Fair bit of corrosion on some of these connectors which I've cleaned away but I may repin the grey one as it's in bad shape.

Attached Images