Horn blares randomly and auto start shuts off after 5 seconds?

Had to pull the hurn fuze under the hood. Horn blares. Not sure of the best way to diagnose this. Horn started about 5 months after the auto start issue. Where I'll auto start, it starts for about 5-10 seconds then dies(shuts off), then it will auto retry, starts for same amount of time, shuts off , then my clicker beeps at me like 3 times. indicating it failed , I'm guessing. . . I'm at a loss and these two issues have been aggravating. Close to bringing it to a shop but I'd really like to save some scratch if I can. Hope someone has some experience with this. Thanks

 

Hello!

We have subforums. Some realize this others dont, so forgive me if you have done this already.

I would start by trying to figure out how your auto start was wired into your truck and then cut the problem in half to troubleshoot.

EDIT: grammar

https://www.tundras.com/threads/ultimate-tundra-wiring-diagrams-collection.81448/

 

Have you had the battery tested? I had weird auto start issues with my Tundra and even though the truck would start normally completely fine, there were weird issues going on electrically. Ended up being a bad battery (which Toyota has been known for over the past couple years)

 

Not everyone understands wiring diagrams though

 

Life's been crazy last few weeks. Finally getting more time to diagnose. I have not had the battery tested. I actually don't see any indicating markings on the battery of manufacturer or brand, unless it's on the bottom and I have to remove. Never had a battery like this before. Here's a pic. But the fact it happened randomly could be a possibility. That or corroded wire or something. I'll be pulling my panels tomorrow and Saturday to trace all wiring, possibly redo some connections to cover my base. I'm not really sure what multimeter settings would help me narrow down if wires are bad or good. I've done wiring on computers, building 3d printers, but nothing too extreme with multimeters. Gonna have to look more into what options I have for diagnosing

 

Depending on when it started, it looks like could've been covered under warranty. 3 yr/36,000 miles for your 2020 model.

 

Be sure to disconnect the battery before you do any electrical work. Modern vehicles get testy when the electrical stuff changes while powered.

 

That looks like just the factory battery to me. I'm not sure the brand that is used though. You could take it in and have it tested with a full load to see if there's a bad cell in it. I'd be hard pressed to think there would be corroded wires though with the truck being a 2020. But you never know!

 

Unfortunately i just rolled over to 93k!