2003 WStar Battery drain

[Selectron]

Hi Darrell, welcome to the forum. On many vehicles, disconnecting the battery negative terminal and then inserting a multimeter set to its current range, or a 12V test lamp, is a legitimate way to monitor the quiescent current (current which flows when the ignition and accessories are switched off). However it isn't that straightforward on the Windstar, because after connecting your meter or test lamp, there's a period of five minutes during which some 550mA will flow (2001 and later models) or some 850mA (1999 and 2000 models). After five minutes that will fall to between 350 to 450 mA for approximately twenty-five minutes, at which time the vehicle will enter the 'sleep' mode where the maximum current flow will be around 25 to 30mA (actually around 15mA steady, peaking briefly at 25 to 30mA each time the anti-theft LED flashes).

So what you're seeing might be just the normal high current (around half an amp) which flows prior to the vehicle entering sleep mode. It's only after thirty minutes or so that you get a true indication of the real quiescent current drain. I'm not sure that chasing excessive current drain is a job I'd want to tackle with a test lamp - a multimeter would be more appropriate, unless it really is a high drain indeed.

Can you could tell us what symptoms you have which cause you to believe you have excessive current drain, how long the problem has been ongoing, etc.

[JsnHardy]

I had this exact same problem. I searched high and low on the internet, pulled fuses, traced wiring switched batteries, stole candy from babies, here is what I found out. It was the alternator. I did not know that an alternator could drain a battery, I thought they were only capable of charging, which threw me for a loop, because it charged fine while it was running. It would drain the battery in under an hour. I even bought a multimeter, but I couldn't figure out how to work the stupid thing. Here is what I did, I unplugged the alternator, and it stayed charged for several days. So I knew that was it. I changed the regulator in the alternator, (requires opening the alternator on mine.) and it has worked great since then.