Parasitic battery drain 2004 Z71 Suburban

crawfordcameron94 · February 18, 2020

I am having the same issue with me 2003 avalanche. Battery drain over night because the IGN A fuse is pulling 180ma. I have don't all the corrects measurements to get a proper reading. I have pulled the ignition switch, unplugged all wires to ignition assembly. I also disconnected the starter and it still reads a constant (.180a). I have looked for bad wiring and have found nothing. I'm clueless at this point! Can someone give me advice?

swathdiver · February 18, 2020

1 hour ago, crawfordcameron94 said:

I am having the same issue with me 2003 avalanche. Battery drain over night because the IGN A fuse is pulling 180ma. I have don't all the corrects measurements to get a proper reading. I have pulled the ignition switch, unplugged all wires to ignition assembly. I also disconnected the starter and it still reads a constant (.180a). I have looked for bad wiring and have found nothing. I'm clueless at this point! Can someone give me advice?

Well, if that were mine, I would fire up the Tech-2 and see if there are any codes stored in the BCM related to that issue. Then I would run a parasitic draw test. You can get access to the shop manual at AllDataDIY and trace the wiring from that fuse to see what is on that circuit. Ignition switch probably.

crawfordcameron94 · February 18, 2020

I have done the draw test it is coming From the IGN A fuse. I have disconnected all wires to ignition and still pulling a .18 draw. It doesn't seem to be the switch.

rjgti · February 18, 2020

look at your starter relay with ign switch plug disconnected

carnau · February 18, 2020

21 hours ago, crawfordcameron94 said:

I have done the draw test it is coming From the IGN A fuse. I have disconnected all wires to ignition and still pulling a .18 draw. It doesn't seem to be the switch.

It's not the switch. If you follow up to my schematic. The IGN A fuse controls multiple other fuses.

First what you need to do is open the door and take a screw driver and latch the door so it thinks it is closed. If you don't do this your meter will read high.

Once the meter is reading the .18amps pull the individual fuses ( brake, 4wd,htr/ac,cruise,hvac 1, ign 3) and see which drops the voltage.

Once you know which drops the voltage report back here with your finding, quote me in the reply (so it comes to my phone) and i will help you further.

rjgti · February 19, 2020

carnau, are you looking at a different schemetic then what is in this thread. those fuses are only hot in the run postion

carnau · February 19, 2020

20 hours ago, rjgti said:

carnau, are you looking at a different schemetic then what is in this thread. those fuses are only hot in the run postion

Right. But if something, for instance the blower motor is shorted slightly on the inside and back feeding the hvac module. The Htr/ac fuse would be pulling the draw. Does not matter if it was in run. Still a drain. You found the Drain. It's on the Ign A fuse. Now we gotta find where it is coming from on that leg.

dan66789 · June 4, 2022

On 1/18/2018 at 9:02 PM, MJM said:

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?

my surburban has been doing the same thing recently, but the difference is, my ignition/starter died. i think it might be just a sign that its going bad