[solved partially] Help with Electrical Problem

I drove my 4.7 06 limited on a 5 mile round trip. After i got home decided to plug my 12 volt inflator into the dash power outlet to properly inflate tires. I started the engine for the 5 minutes it took to check the tires. Then turned ignition off and removed the key. I did not pay attention to or notice any sound from the vehicle went inside my house. About two hours later my neighbor arrived from work and heard a noise coming from the engine area. I walked out and there was a humming clicking sound coming from the engine. My fob would not unlock the door so I used the key. As soon as I opened the door the noise stopped. The battery was so drained the lights would not work. Even the clock would not light up. I jumped it and drove around for an hour charging the battery. Stopped at O'reilly's for a scan. No codes. I could not tell what precise area the noise was coming from. The noise has not come back. Any ideas what the noise was and future return of noise?

June 30,2022 2:33 pm Have found the reason my battery discharged is because of the lights switch being set to on and my opening and closing the door from the passenger side along with starting the engine from the passenger side. The owners manual states that when starting the engine the lights come on and are turned off by opening the drivers door. Not using the drivers door leaves the lights on and results are discharged battery. Still not sure what the noise was. But likely caused when the battery discharged as op have opined. I ran three tests and every time the lights would stay on when not using the drivers door. Every time the lights would turn off as soon as the drivers door was opened.

 

I have drained the battery a couple of times using my 12 volt air compressor on my 06 Limited. If I open the passenger door, turn key on to activate the power plug, the day time running lights come on. The lights will not turn off when I remove the key and close the passenger door. I have to open and shut the drivers door.

Not sure about the sound from the engine compartment but it may have been secondary air pump (smog pump) that runs on cold start up.

 

I did open the passenger front door to start the engine when using the inflator. Also reached through the passenger door to turn ignition off. Possibly caused pump and lights to stay on after I walked away. When I get the chance I will repeat the process to see if the problem repeats itself

 

Let me know what you find out. It's bugged me that I have to make sure to open and close the driver side door after running the radio or anything with the key in the on position from the passenger side.

 

Maybe throttle body butterfly cycling rapidly due to nearly dead battery? Electrical gremlins can cause all sorts of stranger things to happen...

 

I've heard this noise you speak of with my own 1GT and inserting the key, turning all the way ON (not starting) and OFF made it stop. I don't know how long it was happening before I heard it, maybe an hour?

First thing I thought of is the fuel pump, which is what I thought mine was. It's something you'll hear kick on with a lot of cars when opening the driver's door, fuel pump will prime itself and set pressure. But that would be basically under the bed, not in the engine compartment. Although I suppose if you heard clicking under the hood, it could've been the fuel pump relay shorting.

 

I repeated the same steps i went through before the problem. All smooth this time. Hope it was a glitch that never happens again.

 

Throwing this out there 'in case'. Within days of my issue happening, I got into the truck, turned the key forward and *click* everything went dead.

Got out of my truck, texted my friend who'd just hopped off the train from the airport to let him know the truck wasn't starting. 5 minutes later, hopped in the truck, it turned right over immediately. That was like 3 years ago now? Neither has happened since.

Relays tend to click. A firing relay will drain a battery. Many of the relays on our truck are in the box next to the battery. You may just have a relay that glitched, or a relay going bad.

I assumed that no-start condition which followed by some days/weeks was potentially something with my alternator swap at that time, maybe a loose connection or something, but it turned out not to be the case, as I found recently when upgrading to a larger alt.