Engine shut off, unlock doors, starting wipers, gauge and media blinks... All of that while apply brake or use flashers

EXO Dave · March 10

2017 Sierra 1500 5,3L . For a while, especially when it's wet and humid, I had electrical issues while I was using breaks or flashers. For example, this morning, I had to open and close the driver window when I started the engine (message on the gauge); I drove for 2 minutes with a trailer connected to the 7-way plug. At the first road crossing, the engine stopped, wipers started for one lap, gauges and media turned OFF. I turned off the ignition switch and started the engine flawlessly. I was driving for about 20 minutes. The radio (media) blinked 4-5 times during this time. At my destination, I turned off the engine, went outside the truck, and realized I could not remotely lock the doors. I went back in, but no power at all. Few times I turned on and off the ignition switch without improvement. I unplugged the trailer and got back the power. It was the first time it's happened with a trailer, but a few times before, without a trailer, I got all these issues except the wiper. One time was during the night, and trust me, it's not safe at all to lose all lights (Including headlights), engine power, and power steering simultaneously. I checked the negative and positive cables at the battery. No corrosion, play, or cracks there. Does anyone have an idea where this kind of issue comes from altogether?

Thanks

MikeBMW · March 10

Seems like either an alternator issue or a battery issue.
You're going to want to get both tested.

Niklasbraun · March 12

On 3/10/2024 at 4:15 AM, EXO Dave said:

2017 Sierra 1500 5,3L . For a while, especially when it's wet and humid, I had electrical issues while I was using breaks or flashers. For example, this morning, I had to open and close the driver window when I started the engine (message on the gauge); I drove for 2 minutes with a trailer connected to the 7-way plug. At the first road crossing, the engine stopped, wipers started for one lap, gauges and media turned OFF. I turned off the ignition switch and started the engine flawlessly. I was driving for about 20 minutes. The radio (media) blinked 4-5 times during this time. At my destination, I turned off the engine, went outside the truck, and realized I could not remotely lock the doors. I went back in, but no power at all. Few times I turned on and off the ignition switch without improvement. I unplugged the trailer and got back the power. It was the first time it's happened with a trailer, but a few times before, without a trailer, I got all these issues except the wiper. One time was during the night, and trust me, it's not safe at all to lose all lights (Including headlights), engine power, and power steering simultaneously. I checked the negative and positive cables at the battery. No corrosion, play, or cracks there. Does anyone have an idea where this kind of issue comes from altogether?

Thanks

Moisture can really throw a wrench into electrical systems, causing all sorts of trouble like shorts and corrosion. So, I suggest checking all electrical connections, especially the ones that are exposed to the elements like connectors, wiring, and the fuse box. Look for any signs of water damage or corrosion.

Another thing to check is the grounding. Sometimes wonky grounding can cause the symptoms you're seeing. Make sure all those connections are clean, tight, and not rusty.

Also, it's a good idea to double-check your battery and charging system. A weak battery or issues with the alternator or voltage regulator can cause electrical problems.