2000 expedition battery drain
 

Im trying to chase down an issue with the battery going dead overnight. I put an amp meter between the battery cable and battery and with the key off and no doors open I have a 4 amp draw. I have pulled every fuse and relay in both the drivers compartment fuse block and the one under the hood. none of them made a change in the amp draw. It stays at 4 amps.

If I connect the battery I don't hear anything running, clicking or lighting up.

A couple weeks ago my sunroof stuck open and it rained. Windows fogged up inside due to moisture but that has all been fixed I don't have any water on the floor or around the fuse box.

Any ideas? Im about to drive this of a cliff.

Disconnect the feed from the alternator and see if the draw goes away. If it does, the alternator is shorted internally.

After reading some more about tracking down a battery drain I found I did not let the vehicle sit for 40 min before starting to pull fuses. I'll re-do the process correctly tonight and also check the alternator connections.

Thanks

Still scratching my head on this one. After letting it sit for an hour with the door open switch defeated and doors locked I still get almost a 4 amp draw on the battery. I have pulled every fuse and relay in the divers area and the engine compartment and disconnected the alternator + power wire. I don't see a drop in amp draw at all during the process. I tested for a short to ground by setting the meter to resistance and testing between the positive battery cable (while disconnected from battery) and ground and there doesn't seem to be a short.

The only things other than the alternator that doesn't go through a fuse are the starter motor, the starter relay, and the feed to the under-hood fusebox. The interior fusebox is fed off a fuse in the underhood box (F103) and by circuit breaker CB601.

Are you sure your ammeter is working properly?

The rear wiper is known to cause battery drain.
But if your sure you pulled fuse #12 in the Battery Junction Box................


Might pull the BJB and check the underside to be sure nothing has caused a circuit to get shorted on even when the fuse is out.

I pulled fuse 12 and 103 in the bjb and no change. Still a 4 amp draw. I removed all connections to the starter relay on the firewall and the draw drops to 0.9 amps without letting the vehicle sit for an hour. Does the bjb feed come directly from the + battery cable or does it get connected to the lower post on the starter relay?

Per the EVTM:

The BJB is fed from the source post on the starter relay. There should be two feeds from the positive battery post: One goes to the starter relay, the other goes directly to the starter motor.

All connected

https://cimg9.ibsrv.net/gimg/www.for...35da460689.jpg

Alternator connection removed

https://cimg0.ibsrv.net/gimg/www.for...cc03ae3dd7.jpg

Alternator connected, other wire removed

https://cimg4.ibsrv.net/gimg/www.for...f06c1b74b1.jpg

Both connections removed

https://cimg6.ibsrv.net/gimg/www.for...fc12924c46.jpg

So does the solid red wire feed both the BJB and the starter? I think the wrapped connection that I removed in the 2nd pic is just to the alternator.

Pulling fuse 102 and 104 together drops the drain below .5 amps.

Fuse 102 is the (4WABS) Module

Fuse 104 is the Transfer Case Shift Relays, Torque On Demano (TOO) Relay

This rig has AWD, 4H and 4L on the selector so its full time awd.

Off to do more searching.....

No.


The upper terminal wire of the starter relay in the above pic sends power to the starter *solenoid* down on the starter (it does not send power to the starter motor) when the starter relay receives power from the ignition switch via the tan/red wire connected to the starter relay.


The starter motor uses a dedicated cable that runs from the battery positive post to the starter motor solenoid. This circuit supplies power to the starter motor when the upper terminal wire of the starter relay in the above pic is powered and activates the starter solenoid down on the starter.


The red wire in the above pic sends power to the BJB. With that red wire disconnected, the BJB is powerless.

Your meter is hooked up wrong so the readings are likely invalid.

The black plug goes into the common jack, the red plug goes into the 10A jack when the switch is set to the "A" with the gray background and the 10A range is selected (turn off auto-ranging).

What isn't visible is the connections the other end of the meter leads. It would probably be a good idea to have those reviewed.

The meter reads nothing with the black lead on COM and the red on 10A. I checked the fuses and they are ok. As for the other end of the leads, one is attached to the - battery terminal and the other is attached to the - battery cable, both attached using vice grips which are not touching anything else. The + battery cable is attached to the + battery terminal.

That means either 1) there is no current flow to be measured or 2) your meter's 10A current circuit is burned out. The way you had it in those photos is completely wrong and would produce undefined results.

Owner's manul: c.shld.net/assets/own/03482139e.pdf

Your lead connections to the battery and cable terminal sounds right.