Dead Battery in 2 weeks - Parasitic Drain

[jeff in co]

I guess I'll open this idea up for discussion. I may or may not have a parasitic drain, so I did some investigating.

Truck - 2004 Yukon XL 2500, 179k
Battery - Optima Yellow Top
Aftermarket Radio - Alpine head unit with EQ unit
Aftermarket Amp - 2 JL Audio 300/2, 1 Phoenix Gold XS2500, Focal Component, 2-10" Subs

So I looked on YouTube about testing parasitic drains and found one by disconnecting negative cable, and place a meter between the two to see any parasitic load present. What I found was a total drain of 0.07 Amps (70 Milliamps). YouTube suggested 50 Milliamps or lower is acceptable.

The first drain was the hot wire going back to the 3 amplifiers. Once I took that fuse out, I got a drop of 20 Milliamps (sitting at 50 total now). I then pulled the radio fuse from fuse box, I dropped another 30 Milliamps. So with those two removed, my net parasitic drain for the truck is now 20 milliamps total.

To me, that doesn't seem like a huge amount to drain the battery over 2 weeks (vacation sitting at airport).

I tested the voltage of battery, I think it was about 12.5V. I started the truck turned on the radio, headlights, HVAC....battery voltage at idle was about 14.5V. Does this tell me I have a good alternator charge?

Where do I go from here?

 

[Fordum]

Buy a new battery.......
I'm kidding, but it may wind up that way.
Two weeks is 336 hours. At .07 amps per hour, that is 23.52 amp/hours. Not insignificant, but I would expect a fully charged battery to crank a truck after that much loss.
14.5 volts is pretty much perfect, so it looks like the alt is doing its job.
It looks like you need to move the power source for the amps to an accessory switched source. There is no reason for them to be powered up when the key is off. Using acc through a relay, will let you listen to the radio with the engine off.
Also, you need to check the manual for your radio. The only need it has for power while the key is off, is to run a clock if it has one, and to remember any settings. As such, most of them have two power leads.
One, which powers the radio when the key is on, and a second one that needs to be hot all the time for memory and clock. That one usually draws very little power. I occasionally see both leads hooked together. But usually that means the radio is lit up always and therefore noticeable.
You also need to see if you can find that last 20ma. Not sure what else could be on, although the ECM might have a keep alive line so it does not forget its tuning.
In fact, just went back and saw its a 2004, so its almost certain its something to do with the computer.
At this point, I would repower the amps, and get the battery load tested.
Plus, make a point of going outside after dark every so often looking for light. Sometimes something might not be turning off every time.

An intermittent dead battery problem that beat me and my friend for weeks turned out to be a loose latch on a glove compartment. It was on a truck that had a light that came on whenever the box was opened, day or night.
Most of the time the light was off, but sometimes when things were just right, the light would turn on with the door closed. If it had been doing it every time, we would have noticed the faint glow at night, but most of the time it was off.
His young son went out one night to get something he had left in the truck, and happened to mention that it was on.

 

[rampage]

70mA draw would be 70mA in one hour or 70mAh. In 10 hours that would be 0.7Ah (700mAH). So in two weeks (336 hours) that would be 0.07Ah *336=23.52Ah. A yellow top has a capacity of 66Ah according to their website. That tells me that there should be enough charge in your battery if it’s good. I’d have your battery load tested.
The draw for the radio is fine (needed for memory and clock), the 20mA is fine (ECM). But why are the amps drawing power when off? I would think that they should have zero draw if the accessory and power wires to it are connected correctly and not reversed.

Edit: guess I’m not as fast a typer as @Fordum

 

[jeff in co]

Yea, the tests on the youtube links show losses of 1-2-3 amps. Not milliamps. But I do have a little bit of something going on.

The amp wire from battery is very thick, like 2 or 4 gauge. It also has a turn on lead from the radio.

The radio wires are the more complex bundle. I originally had Car Toys install, but they really went to town on the system. Clipped a bunch of wires going into the factory rear controller, then a bunch of stuff shoved in the dash. XM radio module, onstar module, steering wheel module, chime module and a separate radio shack speaker for onstar voice. Quite a rat's nest and taps everywhere!! I've pulled a lot of that junk out and tried to clean it up. Soldered wires and basically cleaned it up. There is a separate lead for ACC and battery memory, and they are separated.

It is interesting to see what type of draws happen. When I connected the meter between the negative post and negative wire, it starts at a higher value. Then after about 15 seconds, drops, then 10 seconds later drops to the final 0.07 Amps. I assume these are modules waking up and then finally going back into sleep mode. Interesting, nontheless.

 

[rampage]

Yea, the tests on the youtube links show losses of 1-2-3 amps. Not milliamps. But I do have a little bit of something going on.

The amp wire from battery is very thick, like 2 or 4 gauge. It also has a turn on lead from the radio.

The radio wires are the more complex bundle. I originally had Car Toys install, but they really went to town on the system. Clipped a bunch of wires going into the factory rear controller, then a bunch of stuff shoved in the dash. XM radio module, onstar module, steering wheel module, chime module and a separate radio shack speaker for onstar voice. Quite a rat's nest and taps everywhere!! I've pulled a lot of that junk out and tried to clean it up. Soldered wires and basically cleaned it up. There is a separate lead for ACC and battery memory, and they are separated.

It is interesting to see what type of draws happen. When I connected the meter between the negative post and negative wire, it starts at a higher value. Then after about 15 seconds, drops, then 10 seconds later drops to the final 0.07 Amps. I assume these are modules waking up and then finally going back into sleep mode. Interesting, nontheless.

Large draw and tapering off would tell me you have a very large capacitor charging up. Still it shouldn’t do that unless in the ACC position.

 

[jeff in co]

Large draw and tapering off would tell me you have a very large capacitor charging up. Still it shouldn’t do that unless in the ACC position.

It happens when I make the final touch to the negative terminal. I actually hear a small little buzzing, like something woke up, then it clicks off (and the draw drops). Really sounds like some sort of factory actuator/module waking up....then going to sleep.

 

[rampage]

Measure the voltage at the wire coming from the radio when in the off position. Then disconnect the ACC wire going to the amps and hook your ammeter inline to measure the current when in the off position. Also, what is the make/model of the amps so I can look those up.

 

[jeff in co]

Measure the voltage at the wire coming from the radio when in the off position. Then disconnect the ACC wire going to the amps and hook your ammeter inline to measure the current when in the off position. Also, what is the make/model of the amps so I can look those up.

I'll have to test some of these things when I get home.

Aftermarket Amp - 2 JL Audio 300/2 (Front and rear component speakers), 1 Phoenix Gold XS2500 (2-10" JL speakers, subs)

 

[ktmoutfront]

Every older car that I work on and do electrical installs, I run a separate feed for the after market head unit and the amps. With separate relays that feed from the battery directly. The relays are fired by ignition switch that is running through another relay that is fired by a shut off switch. This way the entire sound system can be shut off when the car sits for any length of time.

 

[jeff in co]

Every older car that I work on and do electrical installs, I run a separate feed for the after market head unit and the amps. With separate relays that feed from the battery directly. The relays are fired by ignition switch that is running through another relay that is fired by a shut off switch. This way the entire sound system can be shut off when the car sits for any length of time.

That's a good idea and if it does work, that would be 80% of my drain. Thanks for the idea.

https://smile.amazon.com/battery-Is...=B01I5Q7846&psc=1&refRID=ZM768N0BEZCHG0D5PS29

 

[rampage]

It happens when I make the final touch to the negative terminal. I actually hear a small little buzzing, like something woke up, then it clicks off (and the draw drops). Really sounds like some sort of factory actuator/module waking up....then going to sleep.

The buzzing you’re hearing is more than likely coming from the toriodal inductors charging the banks of capacitors at initial startup. You can see them (donut shaped windings of wire) in both your amps below.

JL Audio 300/2

Phoenix Gold XS2500

But like I said before, these should have zero power going to them when the car is off. When you measure the voltage at the ‘remote in’ with the ignition in the off position, if you get 12V then that’s your problem. If you measure 0V then you’ll have to do what @ktmoutfront suggested.

 

[rampage]

That's a good idea and if it does work, that would be 80% of my drain. Thanks for the idea.

https://smile.amazon.com/battery-Is...=B01I5Q7846&psc=1&refRID=ZM768N0BEZCHG0D5PS29

Only if you disconnect all power to your radio too which will erase all your presets and clock. Otherwise just doing this to the amps will cut it down to 28.6%.
But back to your initial problem - get your battery load tested.

 

[89 jimmy]

Agree, load test the battery. I had a battery that showed good voltage, lights came on bright etc. It failed the load test. Battery was bad.

 

[jeff in co]

Yea, next step is load test battery. You did get the right amps but they are way in the back of the suburban in the rear cargo area, so the noise is not the amps. It's actually up front, driver's side of truck. I can hear it in the engine compartment, just on the other side of the firewall.

So feeding the 2 JL amps, plus the Phoenix Gold amp.....what rating would I need for a relay?

And Rampage, you are correct. I'd lose memory on radio so can't do that one.

 

[rampage]

Manual for the JL amps say 40A fuse for each and the manual for the Phoenix amp says 60A fuse so that’d be 80A+60A=140A. Get a relay rated higher than 140A, and let the fuses limit the current.

 

[jeff in co]

Great, thanks Rampage! I was thinking watts and that would of been a TON! Amp fuses make more sense now, thank you. So a 200A would be adequate.

 

[rampage]

Great, thanks Rampage! I was thinking watts and that would of been a TON! Amp fuses make more sense now, thank you. So a 200A would be adequate.

Yep. But before you go spending money on it and the time to install check the voltage on the ‘remote in’ like I said. That might fix this small load draw with a simple relocation of that wire.

 

[Fordum]

toriodal inductors charging the banks of capacitors.

??????

I have heard that noise when hooking up a battery myself, but never paid that much attention to it.
​

 

[rampage]

It happens when I make the final touch to the negative terminal. I actually hear a small little buzzing, like something woke up, then it clicks off (and the draw drops). Really sounds like some sort of factory actuator/module waking up....then going to sleep.

Sorry, thought it was from the amps. Could it be the fuel pump pressurizing the system and resonating? Could try disconnecting the pump at the harness and see. Don’t know what else it’d be.

 

[ZooMad75]

On a gm SUV from 2004 40 to 50 milliamps is normal draw. But you do need to give it about 20 minutes to get an accurate reading with the key off and the doors closed. Many of the modules need time to "go to sleep" and 20 minutes without any input like opening a door does the trick. Otherwise you'll have a higher number that you'll chase down and be wrong. Onstar modules are one thing that does this even if you aren't a subscriber anymore. The bcm can stay awake too for up to 20 minutes.

But if you got it down to 50mA after disconnecting the stereo stuff it's pretty normal. My money is on a weak battery. Even for a yellow top optima, they can have the same problems where they get weak and won't hold a charge. Even 50mA draw will kill it given enough time.