Constant Live Not Required

[Bolly]

Hi all.

I have tried to search but all my results talk about the red/yellow wire and swapping them around to keep the stations, but this is not the problem and my searches are drawing a blank. I am assume the answer is hiding somewhere. Hope someone can point me in the right direction.

So, I am the second owner of my car (Audi A3 1.8t on a 2002 Reg) and it looks as though the original had installed a run of the mill Sony CD player. Nothing special. I swapped this for a Nakamichi 35z a few years ago.

My problem is that that even with the engine/ignition off, the HU pulls a current. If I don't drive the car for anything more then 24 hours the battery is flat and I need a jump start.

To get around this problem, I remove the HU fuse. I obviously lose all the pre-sets (thats ok), but I now want to install a bluetooth device as I am on the road more often. I think this kit pairs the (up to two) phone automatically (I need to check). What I am worried about is that everytime I pull the fuse, I would lose any pairing details which has more importance linked to it.

So my question is, how to connect the HU correctly so that there is not a constant drain on the battery. I assume I need to connect it to the ignition somehow so it only draws power when the engine is on, but I don't know how.

Regards

Bolly

 

[SteveMcB]

Buy a fused tap and either piggy back the wire from one of the existing fuses which is live only when ignition is on or plug into a spare socket like the towbar which is live when the engine is running. It's very easy, a cheap circuit tester will let you identify the best one to use.

 

[pablo]

first off check that you have 12v always on the yellow lead and 12v switched on the red.

£5 would buy a multimeter and its invaluable for this stuff.

 

[easy going Si]

Hi yer Bolly ( I've given you a few pointer's if your not sure go and seek the help of a good mechanic)

A car stereo will always pull a small amount of current to keep its memory but Bolly this seems to be not a car stereo problem I would say by the fact you have a battery flat within 24 hours something else is draining the battery

Even if you had the red and yellow wires were around the wrong it would mean the memory of the unit would only get refreshed when you turned your ignition on and the constant power is only drawing power when you turned the ignition on so I doubt this is the issue

First go around and have a look at the battery itself if it got screw tops check the distilled water level in each cell if its maintenance free but over 4 years old get it tested especially if it has got very high cranking capacity I.E. around 700 amps to 900 amps these battery's have a tendency to blow cells if they are left to go flat

get a friend who has a multi meter or volt meter to check the battery voltage while the car is running should be around 14.4 volts and a decent battery should be around 12 volts to 13.2 volts when the engine is turned off if the battery voltage falls quickly its your battery at fault

A car battery is made up of 6 x 2.2 volt cells which equals 13.2 volt it takes around 10.5 to 11 volts to turn your starter

when you had to jump start your car was it easy or difficult to start I.E. did you have to charge the battery for any length of time or did it start from the jump start this will give you a clue as to the state of discharge of your battery

Hope this helps Simon