Current draw kills batteries

[Brandon1320]

2004 Yukon XL keeps killing my battery.
Bought a new battery because the one in it was 5 years old and was weak starting. I rarely drive the vehicle but after buying the new one, it died on me a couple times. I charged it and it kept dying. Had the alternator tested and it was reading “good” but only putting out mid 13V’s. So I bought a new one.

In the meantime I tried doing a current draw test. It consistently reads mid .085 draw. From reading online everything says around .05 and lower is acceptable. Pulled fuses one by one under the hood and the blower 40 amp fuse when pulled drops the draw down to .006.

Assuming I did all this right, do I need a new blower? Is there any testing I can do on the blower? It has roughly 280k miles.

Here is a video of the fuse in and out. Sorry for the loud background noise, I had a fan going, it’s not as hell in Georgia….

 

[Fless]

50 mA (0.050A) is "okay" but these can typically run a 15-25 mA draw at full rest when everything is good. Pulling fuses isn't the most efficient way to test for parasitic draw, but it's about the only way for the circuits with J-case fuses like you have, once you've eliminated any activity on circuits with the blade fuses. The way to see if a circuit (with a blade fuse) is active is to measure the voltage drop across the fuse test points; that's done without removing the fuse. There's a conversion chart for converting the voltage measurement to an estimated amp draw. Scream if you need a link, or I'll try to add a thread link to this message later.

It's also common for the blower motor resistor to go bad on these, so I would recommend pulling the connector off the blower motor to see if the draw stays. The resistor is specific to the type of HVAC control (manual or Auto). While you're there, pull out the blower motor resistor and inspect for melting, damage, etc. IIRC it takes a 5.5mm driver for the screws.

If you have the Auto HVAC control, know that they can take several hours (up to around 4 or so) to fully go to sleep. Mine takes at least 2 hours and might draw 40-60 mA during the time it takes to go to sleep. That control, however, is on one of the blade fuses so if there is voltage across that fuse, it's still awake.

The cluster is also a common issue for current draw; search "silver migration chevy cluster" and you should get a hit or two about it.

Eric at South Main Auto on YouTube has some good videos on parasitic draw, and there are others.

 

[Brandon1320]

The cluster is giving me issues. I have to knock on it a few times when starting the vehicle to get the light to come on and most of the gauges to work. The mph is stuck at 30 now. But even with the cluster unplugged I still had the 085 mA draw. I’m already pursuing either getting the cluster fixed or replacing it.

 

[Fless]

The non-startup sounds like either a harness connector or PC board solder joint at the cluster connector. I'm not sure what kind of solder was used for these, but I recommend using leaded solder; the lead-free solder is brittle and unforgiving in environments that flex components.

The gauge issue is well known and typically an easy fix, replacing the gauge stepper motors, if you are relatively handy and have basic soldering skills. I've done it for a neighbor with a kit from Amazon. I also replaced a few of the OE backlights while I was in there. Lots of YouTubes out there showing how, but not many show how to mark the gauge needles before removing them so they're accurate when they're put on the new stepper motors.

Pinout of the cluster connector attached in case you need it.

 

[Brandon1320]

I found the source of the current draw. After unplugging everything related to the blower controls and still having the draw, I started following wires under the dash. I found a random power and ground spliced into the factory harness. Followed that up to a gps unit zip tied to the harness with all its other wires cut. Once I cut the wires the draw went away on my meter. I guess at some point it failed and started drawing power?

 

[swathdiver]

I found the source of the current draw. After unplugging everything related to the blower controls and still having the draw, I started following wires under the dash. I found a random power and ground spliced into the factory harness. Followed that up to a gps unit zip tied to the harness with all its other wires cut. Once I cut the wires the draw went away on my meter. I guess at some point it failed and started drawing power?
View attachment 404497View attachment 404498

Car was probably financed at a buy here/pay here lot once.