Parasitic battery drain 2004 Z71 Suburban

MJM · January 18, 2018

Hello,

I have a 2004 Z71 Suburban that kills the battery after a few days with no use. Battery is relatively fresh, alternator charges fine, already pulled the OnStar fuse and the radio fuse.

I measured the draw on the battery with the vehicle off and everything to sleep and it is 0.18 amps. I individually pulled every fuse, relay, and fusible link and when I pulled Ignition A the draw went to 0.00.

My local mechanic won’t do ignition work and the dealership is backed up for weeks.

Any ideas on how to fix this?

thanks!

rjgti · January 18, 2018

if bcm is off ign a then the draw could be from keyless entry scans. everytime some uses keyless entry by your truck it must decied if that code is correct for your truck..if yes unlock doors...if no then do nothing

. this is just a rough idea on how it works

MJM · January 18, 2018

17 minutes ago, rjgti said:

if bcm is off ign a then the draw could be from keyless entry scans. everytime some uses keyless entry by your truck it must decied if that code is correct for your truck..if yes unlock doors...if no then do nothing

. this is just a rough idea on how it works

Thanks for the response.

This is a constant draw while sitting in my driveway without any people clicking their fobs or anything like that.

I’ve sat there and watched it while enjoying a cigar and a drink, no surges up or down......just 0.18 amps all day long.

Edited January 18, 2018 by MJM

carnau · January 19, 2018

How long are you letting the vehicle sit idle before testing the system? You need to at least wait 30 minutes after installing your meter before you can get an accurate reading. Make sure all the doors are closed or at least latched while open. Also MA would be a better more accurate test. Also put the meter in the Min/Max setting and it will record the highest and lowest measurement that way if it spikes and you do not see it you can see it later.

But if you want to chase Ignition A down I will help you.

Here is what is on that leg.

So here is what needs to happen next. Like I said I would run it in MA on the 10A setting and see after 30 minutes what it is reading.

I love to find Parasitic draws. I am the Electrical Tech at the dealership. How do you have the meter hooked up btw?

MJM · January 19, 2018

50 minutes ago, carnau said:

How long are you letting the vehicle sit idle before testing the system? You need to at least wait 30 minutes after installing your meter before you can get an accurate reading. Make sure all the doors are closed or at least latched while open. Also MA would be a better more accurate test. Also put the meter in the Min/Max setting and it will record the highest and lowest measurement that way if it spikes and you do not see it you can see it later.

But if you want to chase Ignition A down I will help you.

Here is what is on that leg.

So here is what needs to happen next. Like I said I would run it in MA on the 10A setting and see after 30 minutes what it is reading.

I love to find Parasitic draws. I am the Electrical Tech at the dealership. How do you have the meter hooked up btw?

Thank you for the response. I wish I had someone here who enjoyed this as much as you do!

I drove the truck for around 45 minutes then parked it in my driveway. Popped the hood (underhood light already disconnected) and placed the meter in line between the negative battery terminal and the negative cable.

Things woke up and I saw above 1 amp, then down to half an amp then down to 0.180 after awhile. I left it that way for several hours and it was still 0.180. I individually pulled every fuse, relay, and fusible link in the underhood block as well as the block on the driver’s end of the dash. The draw stayed at 0.180 except for when I pulled the fusible link for Ign A.

I can do it all again tomorrow, what should I try next?

Coby7 · January 19, 2018

If you pull Ignition A fuse and the drain goes to ZERO then it has to be your ignition switch, it is the only thing you add to the circuit if all the other fuses are pulled. So maybe re-insert the fuse and pull the connector off of the ignition switch. Ignition switch part # 15242754

MJM · January 19, 2018

10 hours ago, Coby7 said:

If you pull Ignition A fuse and the drain goes to ZERO then it has to be your ignition switch, it is the only thing you add to the circuit if all the other fuses are pulled. So maybe re-insert the fuse and pull the connector off of the ignition switch. Ignition switch part # 15242754

Ok.....where do I get to the connector for the ignition switch? Will this cause any problems with the factory alarm or anti theft stuff?

19Sil · January 20, 2018

I had similar problems with my 99 Silverado. After extensive research it ended up being two things. The alternator and the instrument cluster. First I had the alternator tested and was told it was good. Then I replaced the instrument cluster with one from eBay. It helped some but was still slowly killing the battery, so I put a new alternator on and that finally fixed mine.

MJM · January 20, 2018

On 1/18/2018 at 8:17 PM, Coby7 said:

If you pull Ignition A fuse and the drain goes to ZERO then it has to be your ignition switch, it is the only thing you add to the circuit if all the other fuses are pulled. So maybe re-insert the fuse and pull the connector off of the ignition switch. Ignition switch part # 15242754

Thanks.

Working in that now, but I can’t for life of me get the tilt lever to pop out of the column which is making it difficult to remove the lower cover and access the connector.

Ak_grown · January 22, 2018

nothing after market installed? could have a relay latched that might need to be replaced. just an idea to think aboot.

MJM · January 22, 2018

With the help of a large screwdriver I was finally able to pry that stuck tilt lever out, didn’t even break it!

Now I just have to trace the wire from the ignition switch back to a connector. Everything in there is taped together so I need to be careful and not slice anything. Then I can re run the test and confirm it’s the switch.

Edited January 22, 2018 by MJM

MJM · January 23, 2018

So now I’m stumped.

I pulled the connector from the ignition switch and I am still showing 0.180 amp draw.

I tried the mA setting on my meter and it is 0.00. I will try another meter since that might mean the mA fuse is blown on that meter.

Coby7 · January 25, 2018

According to the diagram if you pull the connector at the ignition it still leaves the starter relay contacts in the circuit. Did you pull the fuse block out, maybe you have corrosion on part of the contacts but usually this isn't a consistent draw, it will vary with temperature and humidity. If your parasitic draw is constant then it has to be from a component.

Edited January 25, 2018 by Coby7

carnau · January 26, 2018

On 1/22/2018 at 7:36 PM, MJM said:

So now I’m stumped.

I pulled the connector from the ignition switch and I am still showing 0.180 amp draw.

I tried the mA setting on my meter and it is 0.00. I will try another meter since that might mean the mA fuse is blown on that meter.

The fuse inside the meter could be blown causing it to read 0.00. That's why I said to use the 10A side first. Sometimes people blow them by accident and never know they are blown because the meter will work perfectly on everything else just not the MA setting

Tylerp · April 18, 2018

Try to disconnect the instrument cluster and see if the drain goes away. I had a battery drain that would kill my battery overnight. It turned out to be the instrument cluster. I send it off to automotive circuit solutions for repair. After i got it back no more battery drain. Worked for me but you may have other issues.

Edited April 18, 2018 by Tylerp