Strange Electrical Problem Need Help

[daaduck]

I have a very odd electrical issue and would appreciate any help. I own a 2003 2500HD duramax with an allison transmission and 161,000 miles. The problem that I am having is that there is a constant draw of .272 amps when the truck is off. This causes the batteries to go dead since the truck isn't moved for days at a time. Before anyone says anything, yes both batteries were bad and exchanged. However, when only using one battery (helps in tracking down the problem), the truck will struggle to start on the third day and barely turn over on the forth.

Here's what I have figured out. The ONLY way to get the draw down to a normal .007 amps is to remove either the PCM B fuse or IGN/EDU relay. I know from a very limited wiring diagram printout that the PCM B fuse powers the IGN/EDU relay, and the relay should only power the TCM, ECM, and FCIM. I know that there is nothing wrong with the TCM and ECM because I have completely removed them from truck and the draw is there. Now the FCIM is constantly eating .128 amps (about half the overall) and the draw will drop to .144 amps. I can get this drop by removing the smaller connection on the FCIM, the main harness connections on top of the engine, or the EDU fuse. I can't think of any reason why the Fuel Injector Control Module should be drawing any power when the truck is off.

The .144 amps is what I can't account for. Since the IGN/EDU relay should only supply power to the ECMRVP fuse (which only powers the ECM) and the EDU fuse (which only powers the FCIM), then I should basically get a zero reading by removing both fuses. Magically though, the .144 draw is still there. There isn't anything (light, radio, etc.) that I can find that might be staying on. At this point I can only assume that some random wires are making a connection in some odd location. Once again, any help on this very annoying matter would be appreciated.

[jc1843]

Possible problems-

------the relay is sticking! can you remove the relay to see if the draw goes away?

--------The wiring is shorted- Assume you have checked the wiring for cuts and wear-

--------The ignition switch is bad-- these switches have been wearing on high mileage vehicles. Try to disconnect the switch from the system.

--------Sometimes an added accessory item cause a feed back, which energizes the system. Recommend that you disconnect all added item and check the draw.

I am only guessing like you-- hope this helps.

[daaduck]

1st - I know it isn't a problem with the relay. I have changed it out and also can hear it clicking.

2nd - Shorting wires is what I assume at this point, but since I have no idea where the .144 amps is going, I don't know where to start looking. I have pulled all fuses, any connections, and have almost removed the fuse box. Normally something like wires shorting would be intermittent in everyday situations let alone with me pulling, prodding, and disconnecting anything I can find. But, it is always there.

3rd - The ignition switch is something I will have to take a closer look at.

4th - There are no added accessories on the truck right now. Funny accessories were brought up because I have an edge module, and at first I thought it was the culprit. The edge monitor would/will never shut off. Edge thought it was their unit and reprogrammed it twice before sending me a new unit, but the new one stays on as well. However, the edge module is out of the equation. One, it isn't installed now. Second, I tracked its power draw down to the EDU fuse. When removed, the Edge module draw goes away along with the FCIM draw (just like in the original post) and only leaves me with the .144 amp draw.

Thanks for the suggestions and please keep them coming.

[John-Boy 331]

how about the radio fuse, pull it and see if your .144 goes away, it sounds stupid but i've seen three trucks 2 over 100k 1 under 30k have simular problems and they were all 6.0 gasers and you notice the dead battery really quick with them. just a thought

[daaduck]

yes I have tried the both the radio and amp fuses. In fact I have removed every fuse and relay multiple times and went so far as to photo copy the fuse box picture out of my manual and marked them off individually as I removed them just to reassure myself that I have checked each one. Tomorrow I will try completely removing the radio for fun.

Thanks for the suggestion and please keep them coming.

[daddysLBZ]

I'd bet it's that Edge!!!! Take it off completely [unplug the entire thing!]and then see what it does.If you remove the module from the harness while it's plugged in,then you'll have a bunch of DTC's to clear...Any ses lights?

[Joey-D]

You figure it out? My opinion is bad batteries. That is what was on my old cummins. .272 amps in 4 days shouldn't be enough to drain 2 good batteries.