'98 ECM current draw?

I'm having an issue on my '98... soft to medium clunk while trying to start, battery is a week old, starter is 3 months old. All cables have been replaced with 0 gauge welding cable with ends soldered in place and bolted to the battery terminals. The terminals were reworked last week when putting the battery in.

I have IPFs on it, a computer inside it, an inverter, cb, amp, and an LCD screen. ALL are activated on switched 12, but the battery has been drained without switched 12 being on.

I have heard of the ignition switch not fully disengaging, but cannot find that information again. So, does anyone know the base current draw from the battery on a 98 when it is just sitting there doing nothing? Any other ideas would be helpful as well....

disconnect all the extra stuff and see if it happens again. I seem to remember 5v being needed for computer memory functions but Im not sure how accurate that is

gerroffroad.com said:

disconnect all the extra stuff and see if it happens again. I seem to remember 5v being needed for computer memory functions but Im not sure how accurate that is

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The "keep alive" signals would be +5VDC, but that's drawn from a regulated source inside the component with the VRAM (ECU, radio, instrument cluster, ...)

"It's the volts that jolt, but the mills that kill." Voltage isn't the concern here - it's current. With the key off and vehicle at rest (and switched 12V supply to accessories off,) you should see less than 1A being drawn from the battery at a steady state, and probably less than .5A. Remember, an ammeter is connected in series to the circuit - meaning you will have to disconnect the battery briefly to get an accurate current reading.

If the switched 12VDC supply is through a relay, make sure the terminals on the relay aren't sicking - it's uncommon, but it can happen (I've seen it before.)

Welp, the ECJ5 came to the rescue and was going to jump it off, but the cherokee started right up on the first turn of the key. I have relocated the ground from the block to the starter body because I'm assuming it's a grounding issue for now... hopefully this will do the trick.

To edit:
I've got 0.7 Amp draw. This includes the remote start and computer memory in addition to the ECM memory, so I believe it
s safe to say that there isn't an excessive current draw as I thought before. It could be an intermittent problem, but the battery was good a hour later after it wouldn't start.

As for the relays, I've got so many relays wired up now I don't even want to think of one of them going out. I'm sure I could find it, but mann the locations don't bode well for easy replacement.

0.7 amps is still significant. Most vehicles draw between 0.03 and 0.04 amps with everything shut off.

Giviner said:

0.7 amps is still significant. Most vehicles draw between 0.03 and 0.04 amps with everything shut off.

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True - but he's mentioned the "remote start" and has apparently added a PC with its own KAM, so that would ramp up the draw some. That's why I'd figured he'd be up around .5-1.0A KOEO (Key OFF Engine OFF.)

5-90 said:

True - but he's mentioned the "remote start" and has apparently added a PC with its own KAM, so that would ramp up the draw some. That's why I'd figured he'd be up around .5-1.0A KOEO (Key OFF Engine OFF.)

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i agree that would bump up the requirement but I still think that is way too high even for the accessories mentioned. Something is causing over 10x the normal draw on the battery.

0.7A for 24 hours = approx 17 amp hours per day

With the average jeep battery having about 50 amp hours or so you would draw down the battery to only about 30% charge in only 2 days. It will be stone dead in 3.

0.7A holy crap! Maybe you should unplug the refrigerator you've got in there! Plug that thing in to an outlet at night!