Current draw killing battery(s)

[Keith Seymore]

Howdy everybody.

Vehicle is a 2004 2500HD Duramax.

I have a slow draw which can kill my batteries overnight.

I unhooked the power and jumped one battery with a test light (ie, from battery positive post to test light, then test light to positive cable. One battery only; other battery positive cable disconnected).

I pulled every fuse and relay one at a time in the underhood BEC, the LH end of the instrument panel and inside down by the driver's left foot (boy - are there a lot of them).

None of them killed the draw.

Is there another fuse block I'm not thinking of? Is there something drawing power that is not fused?

It has an aftermarket remote start that I do not use; I have an aftermarket electric fuel pump, which is one of the fused connections that I pulled. Also aftermarket trailer brake controller. Everything else is OE.

Thanks in advance -

K

[Keith Seymore]

Update: unhooked the remote start, unhooked the fuel pump and unhooked the trailer brake controller. Physically removed the radio and HVAC control.

No change.

K

Linking this thread for reference: https://67-72chevytrucks.com/vboard/...d.php?t=842257

['68OrangeSunshine]

Hi Keith,
I just got an '03 Tahoe C/1500. Batt was an EverStart with a 2/24 sticker. [but no warranty paperwork from the PO]. Truck had connection issues in the rain. POS terminal bolt has plier chew marks. Week before last it started OK with a turn tightening the terminal. Volts were 12.7. Monday tried to take it to work -- no start. Grabbed '71 Jimmy and got to work Monday and Tuesday. Weds, I checked the batt, 6.3 volts. W/O paperwork I didn't go to Walmart, I was going to use it as a core on a new batt from Interstate. The guy there said, 'let's see if it will take a charge,' so they have it overnight.
But a drop of six volts on an unused truck seems extreme. Not used to these ''New'' trucks. ALL the door locks open when I go into PARK. Window up/down switches have been playing tricks, and the DS RVM will go screwey when the rocker switch goes over to adjust the PS RVM. Pass Side mirror is stuck at curb view.
[I had it adjusted fine until I showed off my ''new truck'' to my next-door-neighbor, and he said ''what's this do?'' and poked his finger on the mirrors switch and both mirrors went nuts.]
I pulled the 15@ fuse for the RVM but that also killed the window up/down circuits, so I put it back.

[hatzie]

The middle bussed electrical center is next to the parking brake pedal and there's one on each end of the dash.

The trailer brake controller should plug into the mid BEC and there are two trailer connections in the fuse relay block behind the LH battery.

I would check the trailer plug. I've had winter calcium slop make enough of an electrically conductive crud slurry in the trailer plug to drain the battery. I blasted it out with brakeclean and a nylon brush then hit it with battery protectant.

[Randy S]

Disconnect the alternator, including the R1/R2 plug.

[68Gold/white]

Originally Posted by Randy S

Disconnect the alternator, including the R1/R2 plug.

Diode sticks closed, one of most common drain problems.....

[Keith Seymore]

Thanks for reminding me -

It ended up being flat batteries.

I replaced the batteries and all my problems went away. It wants to fly now.

Amazing what you can get used to and begin to think of as "normal".

K

['68OrangeSunshine]

The battery on my '03 Tahoe came back up after a long charge. It seems to be charging and operating normally after 6 weeks.

['68OrangeSunshine]

Originally Posted by '68OrangeSunshine

The battery on my '03 Tahoe came back up after a long charge. It seems to be charging and operating normally after 6 weeks.

The other day, 7/02 , the Tahoe wouldn't start. Fluke across the terminals read 11.11 VDC.
It's possible the Fog Light switch was left on. The driver side one is smashed, and I think the passenger side bulb is burned out. Don't remember any yellow lights [except Turn Signals] on the front. If that Switch is ON -- will there still be a current draw?

I took the '71 GMC to my Dr's appointment. Later, I put the Jimmy none-to-nose with the 'Hoe, hooked up the jumper cables and let it run five minutes, before trying the '03 Ignition Switch. It started fine. I disengaged cables and let the Tahoe run at 1500 - 2000 RPM for 15 - 20 minutes with the daytime headlights off. I shut it down and started it again. It was good.

Wednesday night, it started OK again and I ran it 2.5 miles to the supermarket. I noticed the Cabin Lights stayed off. After I loaded my groceries up, it started again, but I cut off the automatic-On headlights and ran the motor for a few minutes to charge. Then I took off for home. No traffic, so I slipped onto the street without stopping. I had a Green light, so I hit the throttle for home...
Just then a bunch of bright and colored lights were flashing behind me, and I realized -- in my shadow -- my Headlights were off. I switched them on.
I got pulled over but the Cop gave me a verbal warning about driving w/o lights at night, after I explained my screwy electric gremlins.

[hatzie]

Originally Posted by '68OrangeSunshine

The other day, 7/02 , the Tahoe wouldn't start. Fluke across the terminals read 11.11 VDC.
It's possible the Fog Light switch was left on. The driver side one is smashed, and I think the passenger side bulb is burned out. Don't remember any yellow lights [except Turn Signals] on the front. If that Switch is ON -- will there still be a current draw?

I took the '71 GMC to my Dr's appointment. Later, I put the Jimmy none-to-nose with the 'Hoe, hooked up the jumper cables and let it run five minutes, before trying the '03 Ignition Switch. It started fine. I disengaged cables and let the Tahoe run at 1500 - 2000 RPM for 15 - 20 minutes with the daytime headlights off. I shut it down and started it again. It was good.

Wednesday night, it started OK again and I ran it 2.5 miles to the supermarket. I noticed the Cabin Lights stayed off. After I loaded my groceries up, it started again, but I cut off the automatic-On headlights and ran the motor for a few minutes to charge. Then I took off for home. No traffic, so I slipped onto the street without stopping. I had a Green light, so I hit the throttle for home...
Just then a bunch of bright and colored lights were flashing behind me, and I realized -- in my shadow -- my Headlights were off. I switched them on.
I got pulled over but the Cop gave me a verbal warning about driving w/o lights at night, after I explained my screwy electric gremlins.

Factory fog lamps on the 2nd gen GMT800 are controlled by the BCM. The fogs switch off with the ignition.

['68OrangeSunshine]

Originally Posted by hatzie

Factory fog lamps on the 2nd gen GMT800 are controlled by the BCM. The fogs switch off with the ignition.

So I noticed. They go out with the Ignition shut off. The passenger side lamp is not broken and lights up OK.
Started up and ran Friday.

Not sure what caused the system to run the battery down to 11.11 volts last week. I had been trying to run the A/C at full blast, front and back. It's iffy. Sometimes it's cool, and sometimes it's a heater anyway.

I guess the BCM has decided I don't need the Cabin Lights to come on with every door opening. That feature struck me as a waste of juice.

I sent for an LMC Catalog of this vintage. I'm hoping they have the same exploded-diagram format as the 67-72 catalogs.

[hatzie]

The cabin lights not turning on and off combined with the battery drain sounds like one of the ajar switches have gone out.

['68OrangeSunshine]

Would that be in the D/S 8-Button Switch, or the P/S one?
Funny it read 11.97V but started anyway.
Until I sort out the Drain, I guess I should disconnect the Negative lead.

LMC sent me a new catalog -- for 67 - 72. Got a stack of those already.

[hatzie]

The Ajar switches are probably in the door latch assemblies.
Without looking at the wiring diagrams I can't tell if they plug into the window switch module or run back to the BCM.

['68OrangeSunshine]

I had been getting the DOOR AJAR signal last week, but not so much lately.
I'm going to buy these Door Panel repair widgets off eBay.

ebay.com/itm/125739542970

The Switch Assemblies have both been raped by amatuers.
Once I have the Door Panels off, I can try to clean up the interior contacts in the switch assemblies with Qtips and alcohol. Saw a guy on YouTube who did that and saved a Buck and a Quarter on a new 8-Button Switch.

I got the PM, thanks. Next PM, I'll give you my email address -- as my PM space on this forum is very limited.

['68OrangeSunshine]

I pulled the Negative terminal off the battery and attached a 15 watt solar panel. Hope that brings the voltage back up.

[hatzie]

You should be able to clean up the window switches.

The door ajar and not ajar switch is built into the latch.

http://youtu.be/nLppe9m6CJc?si=j2vCUGX16Vthn6eB

['68OrangeSunshine]

Originally Posted by hatzie

You should be able to clean up the window switches.

The door ajar and not ajar switch is built into the latch.

http://youtu.be/nLppe9m6CJc?si=j2vCUGX16Vthn6eB

Thanks for the video.
Jeez, another $200 switch.

[hatzie]

Originally Posted by '68OrangeSunshine

Thanks for the video.
Jeez, another $200 switch.

I'd be tempted to buy a used one once you figure out which one is malfunctioning.

The Impala & Pontiac G6 latch switches can be repaired. I would guess that you can repair the switch in the SUVs Silverado and Sierra too.

['68OrangeSunshine]

Originally Posted by hatzie

I'd be tempted to buy a used one once you figure out which one is malfunctioning.

The Impala & Pontiac G6 latch switches can be repaired. I would guess that you can repair the switch in the SUVs Silverado and Sierra too.

DRIVERS DOOR AJAR was the message. But I can shoot up the others just for GP.

Trying the cheap route first -- shooting Door catches with WD-40 and opening/closing with a screwdriver to work it in.
Brought the Battery up to 12.1 VDC using a big solar panel, 36 x 16 on the dash, behind the windshield. [Negative truck lead disconnected.] Keeping it on for another day in full AZ sun.

Instrument Panel lights behind the Voltage Indicator and Gas Gauge seem to be burned out. Looking at YouTube videos I see they are LEDs soldered to the PC on the back of the instrument board. Seems too fiddly for me to try soldering.

[hatzie]

Originally Posted by '68OrangeSunshine

DRIVERS DOOR AJAR was the message. But I can shoot up the others just for GP.

Trying the cheap route first -- shooting Door catches with WD-40 and opening/closing with a screwdriver to work it in.
Brought the Battery up to 12.1 VDC using a big solar panel, 36 x 16 on the dash, behind the windshield. [Negative truck lead disconnected.] Keeping it on for another day in full AZ sun.

Instrument Panel lights behind the Voltage Indicator and Gas Gauge seem to be burned out. Looking at YouTube videos I see they are LEDs soldered to the PC on the back of the instrument board. Seems too fiddly for me to try soldering.

The 03-07 SUV Sierra & Silverado instrument panels have 11 tungsten filament bulbs with blue silicone caps. Usually it's just the illumination bulbs that burn out cuz the others don't get the mileage.
They're fairly easy to R&R. I would recommend using a decent temperature controlled iron since the cluster, HVAC, and radio boards are thinner than you normally see so it's easy to overheat them and lift the traces.

https://carradiobulbs.com/store-4/20...-light-bulbs1/

['68OrangeSunshine]

Well one Gremlin at a time.
The Batt got recharged by my 36 x 12 solar panel. Brought voltage up to 12.44. Disconnecting and reconnecting the Negative cable produces sparking. So there's some short somewhere.
Meanwhile I shot WD-40 into the Door Latches and worked them in with repetitions.
Truck starts good with juicier battery. VOM reads 14.5 when engine's running. But it will stay disconnected when parked.

[Trucknut57]

Have you located the source of your battery drain yet?

I have close to the same issue and haven't been able too locate my drain either.

['68OrangeSunshine]

Originally Posted by Trucknut57

Have you located the source of your battery drain yet?

I have close to the same issue and haven't been able too locate my drain either.

Since my '71 Jimmy has a Starter gripe, I've been distracted. The field expedient is just to disconnect the Negative terminal off the battery when the Tahoe is parked for a few days.