Hey guys,
I've got a bit if a problem with my radio.
It's still drawing a fair bit of power with the key off, I've double checked the wiring and it's definitely right.
I've tried with two different head units and they both draw power albeit they were old used ones, the first one was already in the van and the second was in another van that had an electrical fire
Radio drawing power
Daniel73 on 10/09/2020 - 11:25
Comments
No, I've checked all that. I'll have another look tonight but I'm certain the wiring is all correct
Is the radio turning off when you switch the car off?
How have you tested it to determine how much current the radio is pulling?
Have you isolated everything else it could be and retested the radio?
Have you removed the radio from the vehicle and tested its current draw on a bench test?
When you plug the original radio back in, does the issue fix itself?You need to make 100% sure it is the radio and not something else in the vehicle that is pulling the power down, as a radio that is off only pulls enough to keep things like the radio station memory and clock from resetting each time you turn the key off.
I did a draw test with the radio plugged in and it draws around 130mA without the radio plugged in it draws around 30mA
Unfortunately I don't have the original radio, they're both aftermarket
I'll do a bench test tonightI forgot to mention, the radio does turn off when I turn the ignition off
Are you measuring this current draw at the battery or between the radio and the wiring harness? This is where you will need to have it on a bench with nothing else plugged in. If you are just taking the reading off the battery cable, it could be any number of systems in the vehicle causing the issue, so this is why bench testing the radio will isolate anything else… And is it a reputable radio (Pioneer/Clarion/Sony/etc…) or some cheap, $30 8 inch display, Android Auto shit box radio from Banggood/Aliexpress?
Another way to test it is to have your multimeter inline with the battery and start pulling fuses. Don't turn the car on (it may pop your mutimeter fuse) just leave it off and get your reading. Start pulling fuses one at a time and look each time you pull a fuse to see what happens to the load. If you get a significant drop on one of them, leave that fuse out and start tracing back where you fault could be. Pull plugs out from that portion of the harness and make sure they are tight and free from damage/contamination/corrosion.
0.1amp is not very high, but may cause issues if the vehicle is left for a long time. Overnight might not be a problem, but a week between drives could be an issue.
I've already done that, isolated it to the radio. so it's definitely something to do with the radio
It's a pioneer, specifically a deh-4450bt
I always thought the accessory lead supplied the most amount of power while the permanent 12v provided a trickle to maintain memory. Latest installs I’ve done the permanent 12v is a large cable and the accessory lead is smaller and obviously just a trigger lead.
Don’t know if that helps.
Yeah, if I unplug the constant it won't turn on
I had a problem with mine where it would occasionally keep running the fan when it was meant to be in standby. It was meant to run for a minute after shutdown but it just kept going until I pulled the fuse…
Can you hear a fan by any chance?Ended up fixing mine by doing a firmware update (USB stick in the front panel, not too painful a process).
Yellow wire is constant power, keeps memory, clock, and other settings alive.
Red wire is ACC, signal wire to turn on and off.
It can draw power from either.I had similar power problems, removing and refitting the fuse always fixed it for me.
Is there a motorised aerial? Sometimes they're powered from the same wiring and seize or don't shut-off properly when retracted.
Have you checked if the glove box light is constantly on?
Check the radio settings for standby time before power off. Change it to 15 minutes if you can on that unit.
Ha ha, I love the ability to measure a current without considering the error in that reading.
Not sure how accurate your meter is as 100mA is only 1w of power and your battery has about 1000w of power in it capacity
100mA is close to the self discharge of the battery anyway, it will lose about 50mA - 100mA anyway.
Your interior light may be 10W which is significantly far more of a drain, and your headlamps are 100w.
What the radio is pulling is squat, and will cause you battery to go flat after approx 60 days.. Yeah.
This is what I was thinking, although, most average car batteries have between 40~70Ah ratings on them. Let’s make it 50Ah for an average.
50Ah / 0.13A = 385 hours at that drain rate, or about 16 days of capacity at that discharge rate. And this is the full discharge capacity, the battery may well not start the car long before it was out of capacity, so possibly halving this figure again as the usable capacity when considering starting the vehicle.
If someone is not driving their vehicle, say, stage 4 lockdown in Victoria, this drain could well prove to be an annoyance over the long term.
For what it is worth, a 10w interior globe would pull about 0.83 amps and 100w globes would pull about 8.3 amps.
On the same 50@Ah battery from above,
50 / 0.83 = 61 hours run time for a single 10w globe
50 / 8.3 = 6 hours run time for A single 100w globe (or two 50w globes)
Is your accessory power cable attached to constant 12v?