Update: Have the 1ohm resistor set up. When car started it was at 1.71 Amps. After about 15 min it dropped to .070 while pulling fuses found that #23 “Aux power out console” was causing.020 drain. Now removed. However every few minutes it would jump up to 1.51 and then back down to .050 I know there is a module that takes hour half to shut off. Fingers crossed after that time it settles. Will keep everyone posted.

 

Update. While pulling fuses inside saw the gage cluster tripping, making clicking noise. All the needles would start to slightly move/shake. May be the problem with drain has been found. Will keep updates coming

 

Hope you didn't actually try starting the car with the resistor fitted (doubt if that could be done) also remove the key from the ignition and maintain all the doors closed.

If possible connect a jumper-wire across the resistor when 1st placed in circuit. Wait for 15mins for activity to calm down, then remove the jumper-wire and measure the voltage across the resistor..

You've made good progress, although 70mA , or 50mA without fuse #23, are not hugely excessive values but it can take quite some time for the vehicle's electronic modules to calm down (some estimate 1.5 hours)

The graph and data below are estimates of how long it takes 80% charged battery to reach half capacity verses parasitic drain current. Much depends on the type of battery, it's age, health, capacity etc, but this is a rough guide to get the idea on the effects of parasitic drain (taken from GM manual) So in theory a 70mA drain would half battery capacity in around 11 days, 30mA in 27 days.


My Hummer has a national GPS tracker system installed on that exact same fuse which adds 50mA, but I prepared to live with that for the added security.

However if the 1.51amp jump continues to occur long afterwards (say 1.5hours) then perhaps you have something aftermarket stuff installed, like an alarm system, tracker, radio, etc?

If you have OnStar pull out the INFO fuse (#58) I believe that as of Dec 2022 the OnStar service was discontinued for older GM vehicles, so it's not needed. I've heard the OS system keeps searching, could that be the drain?

Anything plugged into the accessory outlets will also cause a drain (USB adapters etc.) as the outlets are always powered. It would be good to know where that 20mA is coming from.

BTW nice Hummer 👍

 

Thank you for the compliments. Onstar fuse has been pulled as well. The dashboard was making this clicking sound, the needles wiuod slightly move then it would stop. Ill check for this later. Going to let it sit and will be checking it in a few hours. Could it be the dashboard? There isnt anything aftermarket extra that im aware of. There is dvd player in the headrests. They dont work. Nothing plugged. Will keep you posted . Thx again.

 

... be mindful that the 1 ohm resistor will cause a voltage drop across which may cause some ECU modules to behave erratically or keep cycling whilst they try go into standby modes.

This could be the cause of the clicking sound. Does this go away if you short out the resistor?

Using the jumper-wire allows these modules to power-down or go "quiet" before introducing the resistor into the circuit.

 

Major Update: Believe the draw has been detected and im on the way to being out of the woods. Ill start from beginning. .076

.020 pulled #23 Aux power console

.056

.05 pulled #18 Body Control Module (will plug back in)

.051

.045 #50 Audio system rear seat audio

.006 + BCM back in =.011

Noticed the passenger headset different color than driver. Its not oem. Confident its the DVD in that headrest. Thinking back now I remember doing leather and said that headrest looks different. Also when removing the console to get to on star there were some wires thought didnt look quite write in there. Left the car sit overnight total 16 hours. First time the reading was steady. I had checked the fuses 3 times total. The first 2 times nothing happened when pulling that fuse. Also in regards to the dash. Think that had to do with low power through ohm resisistor. Still going to get gauge redone. Also as a bonus!!! The radiator leak has stopped after running the AC delco tablets. Idke 20 min with heater on max. Drove 20 min. Let sit overnight and 0 leaks. Fixing airbag sensor next. Wow H2 Hummer is back!!! Will keep everyone posted! Thx again for everyones tips and posts really means alot to me.

 

#23 Back in. That controls radio and HVAC unit. Draw is now .030 Fantastic!

 

Sounds like you're on your way, good job👍

 

Thx man, Fixed the airbag sensor too. Put the new one on drivers side. The drivers one was filled with road grime. Was like a lb of sand in the sensor. Still worked. Great feeling seeing that light go out on dash. Next H2 Project fixing paint on Hood. Special project for skid plate. Will keep you posted!

 

I know you got the issue solved but for anyone in the future chasing this. Easy way I've done to check for draw is make sure both battery terminals are really clean on top and sides, loosen the negative so it slides off easy, leave the hood open, doors shut and locked, let vehicle sit for at least 4hrs. Then place the positive of a 10A multimeter on the negative terminal on the cable, the negative of the multimeter on top of the battery post and slowly slide up the negative cable until it is off the post and you can get a reading on the meter. Don't slip and break the connection, otherwise the car alarm will blare and you have to wait another 4hrs. Reading should be 50ish ma / .050 amps ish or lower.