03 z71 myster parasitic draw

silky28 · Nov 25, 2024

Hey all, so I am dealing with a parasitic draw that is killing the batter in under 2 days, but I cannot track it down!

here is what I have tried:

1- verify draw by removing battery ground and running multimeter from ground wire to battery. Was not getting any reading but every time I connected the negative lead there was some sparking so it was surely pulling amps. I assumed multimeter bad.

2- switched to using an amp clamp. I clamped the negative wire right before the battery and got a reading of 610 miliamps. To verify the clamp was working I flipped on the headlights to see if amps spiked on meter - they did.

3- I waited 30 mins then did a voltage drop test on the under hood fuse panel. I couldn’t find a single fuse that had any voltage drop. So make sure meter was working I turned on headlights and found voltage drop on that circuit.

4- after waiting again I voltage drop tested the inside fuse box and again, nothing drawing power. So then I got annoyed and removed all fuses and relays from the engine fuse block, all fuses relays and wires from the inside fuse block, and everything from the instrument panel fuse block. On top of that I removed commonly problematic things like the radio, hvac controls, instrument cluster and drivers door lock switch. The draw is still there!

I am getting to my whits end with this. What can be left? Starter solenoid?

Donal · Nov 25, 2024

i may be misundersting what you have done, but sounds like two normally positive wires may be shorted together.
check alternater for amp draw as well

silky28 · Nov 25, 2024

Vehicle is drawing power when off. I’ve tried to use voltage drop method to find circuit drawing power but with no luck. I then started yanking fuses and waiting for the amps to drop but again no luck. I removed every fuse/relay in the vehicle and it is still drawing amps when off.

I am wondering if it’s the starter/starter solenoid. It is not the alternator, I have disconnected it and the draw remained.

Donal · Nov 26, 2024

maybe search the wiring diagram for 'hot at all time' circuits and find a frayed or damaged section touching a ground lightly.

swathdiver · Nov 26, 2024

silky28 said:
Hey all, so I am dealing with a parasitic draw that is killing the batter in under 2 days, but I cannot track it down!

How old is your battery and what is its state of charge in the morning after sitting at rest all night?

When the car is sitting, modules wake up, do their tasks, and shut down again. They're not always drawing power when the key is off.

silky28 · Nov 28, 2024

The battery is old but still serviceable. When I do the tests I have it on a 1a trickle charge to keep it topped up. Well that is the problem right...something is draining .6 amps constantly.

I am pretty sure that it is not to do with the starter because when I put the amp clamp on the wire going to the starter I get no reading. I am quite certain it is something that connects to the fuse box because the amp clamp reads an amp draw on the wire the goes from the battery to the fuse box. Other than that I have no idea and I cannot find a fuse that is drawing amps through voltage drop testing.

ivin74 · Nov 28, 2024

silky28 said:
Vehicle is drawing power when off. I’ve tried to use voltage drop method to find circuit drawing power but with no luck. I then started yanking fuses and waiting for the amps to drop but again no luck. I removed every fuse/relay in the vehicle and it is still drawing amps when off.

I am wondering if it’s the starter/starter solenoid. It is not the alternator, I have disconnected it and the draw remained.

Do you have any after market stuff?
Radio, LED lights, headrest TV, inverter, ect?

I would start there first, I had a similar situation and it ended up being an inverter hooked up straight to the battery. China made headlight LEDs also draw power while the vehicle is off.

These vehicles are known to draw power from a bad instrument cluster.

Fless · Nov 28, 2024

Having any sort of charging device on the battery when testing for parasitic draw will skew the results. You'll be reading an inaccurate draw due to the contribution of the charger.

Start with a solid battery and be careful of the polarity of the inline ammeter.

EDIT: what amp clamp are you using that will accurately read DC mA? There ARE such devices but not all do.

mike singleton · Dec 2, 2024

silky28 said:
Hey all, so I am dealing with a parasitic draw that is killing the batter in under 2 days, but I cannot track it down!

here is what I have tried:

1- verify draw by removing battery ground and running multimeter from ground wire to battery. Was not getting any reading but every time I connected the negative lead there was some sparking so it was surely pulling amps. I assumed multimeter bad.

2- switched to using an amp clamp. I clamped the negative wire right before the battery and got a reading of 610 miliamps. To verify the clamp was working I flipped on the headlights to see if amps spiked on meter - they did.

3- I waited 30 mins then did a voltage drop test on the under hood fuse panel. I couldn’t find a single fuse that had any voltage drop. So make sure meter was working I turned on headlights and found voltage drop on that circuit.

4- after waiting again I voltage drop tested the inside fuse box and again, nothing drawing power. So then I got annoyed and removed all fuses and relays from the engine fuse block, all fuses relays and wires from the inside fuse block, and everything from the instrument panel fuse block. On top of that I removed commonly problematic things like the radio, hvac controls, instrument cluster and drivers door lock switch. The draw is still there!

I am getting to my whits end with this. What can be left? Starter solenoid?

I had a 2004 Yukon XL Denali with a great Bose system and when I was talking to an old experienced tech at a radio shop, he checked it out and was right about the known problem with the Bose AMP that is located at the bottom of the center console. Then I checked on line and there were lots of other reports of this AMP causing the draw. Since I replaced it with a used one, I never had an issue but I understand that there are some specialty shops that repair these devices. Just check it out - disconnect the AMP and let us know if you still have the draw. I'll also say that that 04 had one of the best sounding stereos for sure. (Much better than my 2019 GMC Yukon Denali or my 2011 chev suburban LTZ) Apparently it's a known issue.

adriver · Dec 2, 2024

ivin74 said:
Do you have any after market stuff?
Radio, LED lights, headrest TV, inverter, erc?

I would start there first, I had a similar situation and it ended up being an inverter hooked up straight to the battery. China made headlight LEDs also draw power while the vehicle is off.

These vehicles are known to draw power from a bad instrument cluster.

Yeah this. Anything aftermarket is first suspect. Especially stereo equipment. Amps have a Large power wire, and a very small remote wire. That remote wire acts as a switch to turn off and on, when they receive power. That switch wire is connected to the remote wire on the head unit so your amps only come on when your head unit does, and your head unit shuts off when it loses accessory power.

The other things that are known (not that common problems) would be, are you losing accessory power after you open the doors? A stuck door switch, or a bad ignition could be causing you to not lose accessory after you've shut off the vehicle and opened the door.

Donal said:
i may be misundersting what you have done, but sounds like two normally positive wires may be shorted together.
check alternater for amp draw as well

Another thing that happens with NBS models, is two wires in a connector can create an unintentional circuit. The ground can get too much resistance, and melt the plastic surrounding it in the connector, which leads to two connector pins creating a hot circuit that shouldn't be. You could try pulling and inspecting the connectors, under the fuse panel, and under the brake pedal (to the left), where the MBEC connector is. If it's this, it will be obvious by just looking at.

03 z71 myster parasitic draw

silky28

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Donal

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silky28

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Donal

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swathdiver

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silky28

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ivin74

05 NBS Nali

Fless

mike singleton

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adriver

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