PiP won't start, a clicking sound won't stop

you likely need a new 12v battery.

definitely try charging it, the charger also charges the 12v. if it won't take a charge, you'll need to get a trickle charger or a new battery.

how long were you gone? i was gone for 7 weeks, and mine started fine.

 

that's not long, hopefully that's your only problem. if it were me, after 6 years, i'd just get a new one, but it could last a few more if you can get it charged.

 

So, was that it?

 

My trunk was unfortunately left up a few days ago, and had a run in with the opening garage door, which ripped up the plastic spoiler so it doesn't sit properly. Fortunately the glass and door appeared to be fine. My next trip was today, which went well, and I closed the trunk after shopping, leaving the garaged car unlocked.

An hour later the trunk wouldn't open, the key fobs didn't work, and a check battery warning showed on the dash. The battery, which was 12.67 volts a week ago at the fuse box, was now 4.8 volts, and a humming sound was coming from the spark plug enclosure. A friend says the 12v battery is likely the issue, so I'm planning to crawl in the back to test and remove it tomorrow.

However in the meantime, the humming under the hood has changed to a very loud clicking sound, which sounds quite threatening. Is this a cause for concern, and is there anything I can do to stop it, like disconnect a relay, or is it fine to just wait and disconnect the battery in the morning?

 

This is just a theory, but if the garage door tweaked the lift gate and it didn't latch all the way when you closed it, the inside lights might have drained the battery.

Had you tried locking the car in that condition, the car would have beeped at you.

Did the noise under the hood start after you opened the driver's door to check the battery voltage? If so, that's probably the brake accumulator pump trying to do its job without enough voltage. If it was doing that when you first approached the car, then I don't know.

 

put a 12v jump on the jump point under the hood, then you won't have to crawl in back.

better yet, try charging the car, which also charges the 12v, might work.

in any event, replace the battery if it is original

 

That's assuming there is enough power to get the charger to start up. If the 12V is too far gone, the computers won't wake up enough to get the charger going. But worth a shot for sure.

 

excellent point!

 

Thanks much for the helpful replies. The led inside lights were not on. I don't know if the noise was caused by the brake pump, but it sounded entirely different. The battery was down to 5.4 volts only 1 hour after driving. The evse did not work. The 3a charger red light kept flashing and the battery was not charging.

The noise had stopped by morning, and the under hood reading was 3.3 volts. However, the battery with cables off was 6.9 volts, which went to 11.8v in 1 hour, and 12.44v in 5 hours of charging. The charger will stay on all night. I have normally kept the charger on all the time when not driving, but had not used it for ten days.

This result is encouraging for the battery, which causes other concerns. However, my friend assures me that the battery is the problem, nothing else, and that it needs replacing. I believe it's the original battery. I'm hoping that Costco carries this size, whatever it is, and will call them in the morning. Likewise I will briefly reconnect the battery, to see if the car is functioning properly.

 

this is key, once the battery is back up, reconnect to determine if it has a draw on it when just sitting there.

 

It sounds like there was a significant electrical load on the battery overnight. As @Yea Right, said, you should check for that as soon as you reconnect the battery.

 

The charger light was green this morning, with the battery at 13.64 volts. An hour later off the charger the battery was still at 13.04v. I connected the battery, there were many clicks, the flashers were on and all the dash lights were lit. The ignition light was on, which was strange. I pressed the ignition, turned off the flashers, the dash lights went off, and the car appeared to be in normal condition. The key fobs worked, the evse worked, and the trunk door was able to be opened.

The load test took about a minute to calm down, and settled at .020 amps. Is that good? I unplugged the battery for an hour, connected it again and this time the car remained calm. The battery is at least 5 years old but appears to be in good condition, this evening still at 12.7v. I've since discovered how to open the hatch from inside.

The drain seems to have been caused by a short, perhaps by something that triggered the ignition to accessory mode. When we returned from the previous trip, I turned off the ignition, and was adjusting the windows, which my friend interrupted by opening the side door. Could that have triggered the ignition? Then I emptied the trunk, and returned an hour later to find the previously described condition, with the battery already down to 5 volts.

 

check it in the morning

 

I agree with @bisco. I don't see how the window event could cause it, but I would be concerned that there might be a short in the circuit for the middle brake light in the spoiler.

 

Ten days after charging the battery, with no charging in the meantime, the battery is still at 12.67 volts.
The hatch brake light and latch do not have a short. The charger/conditioner is now going back on the battery.

The drain was caused by holding down the master passenger window button (which no longer works) right after the car was turned off, while someone else opened the passenger door. This put the car in accessory mode, causing the battery to run down and the clicking noise, which weren't noticed until later. Fortunately the battery has been well maintained, and remains in good condition.

Notes: (1) don't press master switches when the car is off, (2) make sure the ignition is off (power light is green), (3) keep an extra 10mm wrench in the car, (4) if nothing else works, disconnect the battery for 30 seconds and reconnect it, (5) keep the battery charged and well conditioned, as usual, (6) consider getting a battery pack, connecting charging plugs and maybe a quick release to the battery, (7) replace or glue down the plastic spoiler, (8) maybe replace the master switch. Duct tape has been working on the spoiler, but doesn't stay down very long. Thanks again for the helpful responses.

 

Wow!! Who would have guessed? This sequence has happened to me several times and I guess I've been dodging bullets. Nice detective job.

 

is it a salvage vehicle, accident or rodent infested?

i'll test your theory, but i don't think holding the master switch while someone opens the passenger door with the car off is going to do anything except turn on the dome light