Our 1998 Ford Expedition XLT 5.4 seems to have two basic issues right now. I've done some reading on the forums and tests of my own, but can't pin down the problem. The truck is currently at the dealer, who just asked to keep it over night to look further at it.

(a) The truck appears to have an electrical draw issue. During the winter, we drive the truck once every few days. During the summer, the truck sits for up to a month at a time. Approximately 3 weeks ago, we came out to find the battery dead. The battery was charged with an external charger and within two days was dead. Battery voltage was monitored daily and dropped 0.1 V to 0.2 V per day (max 12.5 V, min 11.8V). Since then the battery has been disconnected any time the vehicle is parked and the battery has not died.

Battery drain was monitored and was 80 – 90 mA for most circuits. Battery drain was evaluated by individually removing individual fuses and monitoring current draw between battery + and cable. No difference was seen when individual fuses were removed, with the exception of circuit 15 (GEMS/PATS). When circuit 15 was removed, draw dropped to 31 mA.

The dealer said that our draws were reasonable and draws of up to 250 mA would not drain the battery that quickly. The dealer also indicated that due to the power saver circuitry, they would need to monitor over a longer period of time.



The alternator and battery was replaced 10/04/2006 (107,000 miles). The battery was tested both in vehicle and off vehicle at two different shops and passed (July 7, 2008). Battery voltage when running is 14.1 V.
The starter was replaced 9/28/2008 (114,700 miles) and 5/23/2008 (123,719 miles).


(b) The second item is a whistling sound when started and cold. It happens both in gear or in park. It's not a HVAC sound, we isolated that part quickly. It doesn't really sound like a belt squeal (already replaced that one). The sound does not increase in direct relationship to throttle.

-Eric

 

a) If you have the air ride suspension with a slow leak, the pump will kick on occasionally to re-level the vehicle.

The rear wiper motor can be getting power if the wiper arm is not placed on the motor pivot correctly. The motor has to be able to go down to a certain point in order to turn itself off. If the arm is installed too low then the arm hits the stopper on the rear gate, but the motor has not yet reached to off position.

b) A vacuum hose leak at the back top of the engine is a common problem.

 

No air suspension, but the rear wiper motor would be one to check. Is there an easy way to check that one - or disable it to see if it's the root cause.

Vacuum leak - sounds reasonable. Will check.

-Eric

 

You could pull it's fuse and connect an ampmeter across the fuse terminals. If there is a draw the meter will show it.

 

Hello All, Just signed up today, hoping to find some information. Great forum, I have been lurking for months, and finding really helpful answers. I have posted elsewhere, but don't know how to do a link yet. This seems to be a more current discussion of the same issues. Here goes: Just fought through a Battery Drain problem on my 97 Expy EB. I had been happening for so long, it killed one of the battery cells. Found drain to be in Radio, CD Changer, RICP circuit. Doese anyone know what is acceptable "power off" drain for CD Changer (I had 120 milliamps) Also the Rear Integrated Control Panel on the back of the console (I had 50 milliamps here) So far, I have disconnect both items and now have 10 milliamp draw after truck "goes to sleep" ANY Help is appreciated

 

The dealer was not able to find a draw or whistle. Actually, the dealer seemed convinced that it was from inside the cabin (whistle occured regardless of HVAC setting, parked, or whatever).

I changed the worst two portions of the vacuum lines and the whistle appears to be gone.

Woody - could you check a CD vendor to see if they publish draws for their units? While it might not be exactly the same, it might get you in the ball park.

-Eric

 

Between the two you have a 170ma per hour draw. In doing the math that's about 4 amps per 24 hour period. At that rate, if the vehicle wasn't run for 3 months (no battery recharge), the battery would've been drained about half way. I'm basing it on a 700-750 amp capacity battery (90*4=360 amps drained.)

 

Alloro, Thanks for the reply, ERB, Sorry to threadjack! I am new and don't know how to link posts yet. I mentioned in another that my alternator was replaced because we suspected it was the main current drain, before proper troubleshooting. By the sounds of it, this was most likely what had killed the battery. I can live with the 170mA drain for the sake it will not kill the battery too quickly, but I have read that CD Changer should not have any "power off" current flow. I'd like to get it repaired if possible. Any suggestions?