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Discussion Starter · #1 ·
I have a 2000 4.6, and within the past 6 months, the battery will die if I leave it sitting for over one or two days. I have a brand new Optima gel cell battery, and a new alternator. I don't see any lights that come on or anything, and there are no aftermarket parts that could drain the battery. Is it the BECM thing, or is there anything else to check? Does anyone know where to get another working BECM for a reasonable price? Please help!!!
 

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It is possible that the battery is not holding it's charge and I have never had any nice things to say about gel cell batteries anyway. I have 5 Odysseys of various ratings (all dead) in my garage. I now run normal wet cell batteries.
I would check the battery first. If this checks out, then you do have a power drain or interference somewhere that's keeping the BeMC awake and causing your drain.
 

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petespoker...
You're going to need a multimeter to see what voltages are going round...
What does the battery have at rest? What's the voltage at the terminals with the vehicle running? Next, put the meter inline between the positive terminal and the positive cable to see what kind of drain there is (hopefully on the miliamp scale). You'll then need to reference that number with the shop manual to see if it's in an acceptable range...

Bogatyr
 

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Discussion Starter · #6 ·
Well, this is the second battery, and according to the auto parts store, it checks out well within specs. I am assuming it is something else. Are there anyother signs to look for?
 

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petespoker...
Well, I'd check to see what the alternator is putting out. If that's ok, and there is an excessive draw on the battery when the vehicle is not running I'd suspect something like the becm...but I'm a series guy...I can't tell you any specifics on testing something newfangled like a vehicle with an alternator...the shop manual would have, I'd assume, some testing procedures for the becm...
Bogatyr
 

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It is possible that the BeCM is not going to sleep. To check, look at the red dot that shows the gear position. The light should glow dim when the ignition is switched off and eventually turn off. You have to check it with out opening any doors. As soon as a door is opened or the remote is activated the BeCM will wake up.
 

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Old trick...

Hi,
One old trick to find whats still drawing current is to close all doors, turn everything off, take the key out of the ignition.
Then, slowly pull one fuse out of the fuse box at a time, slowly put each fuse back in, if there is current draw you will see a small amount of sparking as you push the fuse back in that indicates some current draw across the fuse.
This is not a 100% accurate way of fault finding, but it will tell you what's drawing from the battery after everything is turned off.
Good luck,
Andy :)
 
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