Electrical Issue

I was listening to the radio in my 2011 with the key in the accessory position on my lunch break and when i turned the key off to go back inside a kinda loud pop came through the speakers like an amplifier shutting down in the old days but i didnt think to much about it even though it had never done it before so when i was ready to go home 3 1/2 hours later my truck barely started like the battery was almost dead or something but it did start and i drove home and now everything is fine system is charging and it hasnt happened again. Anyone have any ideas? Thank's

 

Don't sound good. Hopefully, your battery will not be dead in the morning. I hate electrical bugs.

 

Have you had the battery tested? Could just be a battery that is on it's way out.

 

30 minute lunch? You know how old the battery is?

Like Dm93 suggested, test the battery. Clean the terminals and posts with a battery brush if they need it.

 

Thank you for the suggestions. The battery is a Die Hard Gold about a year and a half old. Battery terminals are clean and have terminal protection sprayed on them. I haven't had anymore problems with it starting but just dont understand why it did what it did the one time.

 

A year and a half old battery with clean terminals and protective spray, you’re probably ok. If you have a multimeter you can test it yourself.

Hook it to the battery, set it for dc volts, set it for peak low if it has that feature. Start the engine, record the lowest voltage reading. Then turn off the peak low to see how high the alternator volts are.

The loud pop I’m not sure.

 

Have you tried to reproduce the sound? Have an audio recorder ready to go.

 

Ok the same exact thing happened again like it did when i asked about it last October. I never did find out what it was but everything checked out good back in October including the battery and charging system. Just jumped started and never had another problem till now. Same thing jump started it and everything is working fine now and still cant find or recreate the problem. It is an aftermaket stereo system but i installed it at least 10 years ago and have never had any problems with it. Just wondered if anyone had any more suggestions? Thanks

 

How is the amplifier wired? Is it a separate outboard amp, i.e. the head unit is one box, and the amp is somewhere else?

This sounds like possibly an outboard amp did not shut off correctly when the key was removed. Maybe an intermittent failure on an accessory relay, leading to the amp still getting power even after the key was shut off.

The clue that stands out to me is the "pop" sound which is what could occur if the amp loses low-level audio input signal while still receiving normal +12V power.

Depending on the size & type of amplifier and the condition of the battery it's possible (?) that the amp draws enough standby power (without any audio signal) to drain down the battery.

 

What brand alternator does it have? The reason I ask is because I had installed an autozone alternator in one of my previous vehicles. Big mistake. What would happen is it would work perfectly fine, then suddenly stop working until the battery died, I’d get a jump, then it would go back to working fine again.

We’re trying to help. It would help us help you if you answer questions previously posted.

Have you had the battery tested?
30 minute lunch? You know how old the battery is?
Have you tried to reproduce the sound?
How is the amplifier wired? Is it a separate outboard amp, i.e. the head unit is one box, and the amp is somewhere else?
Did you perform a starter voltage drop test? If yes what were the results?
Have you cleaned the battery terminals and posts with a battery brush?
What brand alternator does it have?

 

Im sorry it took so long to get back with everyone trying to help me out. Had some family problems and haven't had a chance to even really look at my issue. The alternator is a oem from toyota. It was replaced about 3 years ago(2011 model TRD Sport) Terminals are perfectly clean. Have had electrical system tested. This same system has been in the truck for over 10 years and has never had any issues. The battery was replaced when the new alternator was replaced. I don't know how i could reproduce the sound when i have listened to the stereo at the same volume for months and the one day it just out of the blue did the loud pop through the speakers and the the truck wouldn't start. i have taken all the fuses out and haven't used the stereo since then. I have a Sony head unit with a 4 channel amp and a bridged amp on the subs. Just afraid to use it again because i don't want to be stranded someplace with a dead battery. Everything seems to be just fine when the stereos unhooked.