Alrighty, heres the Scenario...

Have a 6 cylinder car, swap engine with 406 small block, on top of cooling issues, now i have electronics problems. Seems that there is a constant 1.35 amp pull from the factory wiring that is causing my car to kill the batteries. I had to retain the factory computer to keep the factory guages and what not working, so any ideas??

thanks

-steve

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92 RS/SS FrankenCamaro
More mods to list than time to do it in

www.groundzerocustoms.org

 

You can isolate the device that is drawing excessive current by removing fuses one at a time until the current draw drops.

If all the fuses have been removed (did you remember the fuel pump fuse by the battery?) and you still have the 1.35 ampere draw, start removing connectors, such as to the alternator.

If you still have not found the source of the current, try the things that are permanently connected like the ECM, radio, alarm, etc. until everything is disconnected. You'll find the source sooner or later...

The computer should draw ~60mA (0.06 ampere). The radio memory, alarm and any clocks will also add to this. A typical totat current draw with the engine off should be around 100-200mA (0.1 - 0.2 ampere).

 

I was curious to see exactly how much the parasitic load was on my '91 Z28 so I measured it to give you an idea of a typical example.

27mA. That's 0.027 amperes, and is what the ECM and alarm draw with the engine off. This figure will vary depending upon what you have connected to the car that draws current with it off, like the alarm, radio (memory), clock, etc.

The 27mA does not include the radio, which is connected to a rear mounted Optima battery, isolated from the front battery by a relay. I would imagine that it (radio memory) doesn't draw more than a milliampere or two - maybe even less (nano-amperes?).

[This message has been edited by Stuart Moss (edited August 09, 2001).]

 

Well the whole thing with the fuse box is i dont know what is working and what is not. It was wired by a guy that does wirign for a living and supposedly done right. but being as it is i dont know what goes to what...a nd i dont think anyone knows now. Ive unpluggged all the accessories ive added, and that didnt make a difference. Im beginning to belive im going to have to rip the entire dash oout just to track it down.

-steve



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92 RS/SS FrankenCamaro
More mods to list than time to do it in

www.groundzerocustoms.org

 

I understand. It really doesn't matter if you know what goes where, at least not yet. I only want to isolate the current source. Then we (you) can determine what is connected to it. If the current does not drop when removing a fuse, you can replace it (you don't need to keep everything disconnected).

With all the fuses removed, I presume that the current never dropped with the key out, dome lights off, etc.

Now, with the ampmeter still connected to the battery to monitor the current draw (still at 1.35 amperes?), start removing things that are permanently connected to the battery, like:

1. The ECM. You could remove the connector to the ECM which is, on my '91, just behind the battery. It is a connector with a single wire. You could also just remove all the connectors to the ECM.

2. Remove the wires to the alternator.

3. Disconnect everything to the radio and amplifiers, etc.

4. Disconnect the alarm.

How many amperes are being drawn?

If you still have the 1.35 ampere current draw, start removing connectors/wires to isolate it. Sooner or later you'll identify the source.

[This message has been edited by Stuart Moss (edited August 10, 2001).]

 

Ok stewart, ill give that a shot this week some time. I thank you for your input. I think that its gonna be a long and drawn out proceess though. :*(

Thanks again.
-steve

------------------
92 RS/SS FrankenCamaro
More mods to list than time to do it in

www.groundzerocustoms.org