Car electrics completely dead !

[ac427]

I drove 15 miles without issue to visit a friend and parked the car.

About 5 hours later (around 11:30pm) i walk up to the car and and press the key fob to open the door. The door pin pops up and i get in.


Because it is late i want to start the car and pull away quickly so as not to upset any neighbours.

I put the key in the ignition switch and quickly turn it to position 2 and then to position 3.

The lights on the cluster briefly flash on and go out and then the car is completely dead.

I turn the key back and fourth in the ignition switch but there is absolutely no power, no lights on the cluster, no nothing.

I get out and the window doesn't drop to clear the upper seal. It's dark, so lean across to push the passenger door button down. I then close the drivers door whilst gently coaxing the window into the roof seal and lock it manually with the key in the door lock barrel.


I stay overnight and try to open the car door with the key fob in the morning. Once again nothing.

I open the boot (trunk) manually using the key in the bootlid lock.

I then disconnect the earth lead from the battery. I then short the positive lead to the earth lead for a few seconds. I put the earth lead back onto the negative terminal of the battery.

As if by magic, the lights inside the boot come on and i hear the DVD Nav computer start to boot up.

I return to the drivers seat and start the car on the key without issue.


Has anyone experienced a situation like this?

[sapote]

Sounds like a loose cable clamp at the battery posts

[liam821]

Sounds like a loose cable clamp at the battery posts

Yeah, this. Sounds like one of the battery cables wasn't tight.

[sapote]

OP, next time before doing anything, use DVM to measure batt voltage DIRECTLY on the two posts. If it's below 12.5v then batt is issue or charging issue.

[ac427]

Yeah, this. Sounds like one of the battery cables wasn't tight.

I think there may have been some movement on the positive terminal now that i have checked it at home.

[ac427]

OP, next time before doing anything, use DVM to measure batt voltage DIRECTLY on the two posts. If it's below 12.5v then batt is issue or charging issue.

Sadly, I didn't have my Fluke meter with me but I'll keep it in the car from now on.

I've just checked and the voltage was about 12.2v

With the battery out of the car the voltage is 12.4v

I've put it on a decent CTEK battery charger.

Am i right in thinking the hedgehog resistor can be a drain on the car even with the ignition off?

One strange thing i noticed on the morning when managed to get the car started was, the OEM widescreen display had slightly tilted, as if it was about to open, to accept a tape cassette.

[ugaexploder]

multimeters can still give false positives...most of us should have a cheap battery tester. need to put some load on it and do discharge test to give better indication of battery health.

[ac427]

multimeters can still give false positives...most of us should have a cheap battery tester. need to put some load on it and do discharge test to give better indication of battery health.

Agreed. I have had it tested previously on one of those devices that measures internal resistance and it passed.

As you say a proper load test is probably better.

[sapote]

I've just checked and the voltage was about 12.2v

With the battery out of the car the voltage is 12.4v.

How long the engine last run before you measured these voltage? Too low : either alt not charging or current draining overnight