First off, thanks for the add. Been on here quite a bit and seems like a lot of good info.
Bought my soon to be 16yr old kid a 2003 5.4L Supercrew Lariat Leather 4wd. All original, no aftermarket add ons except for K&N Air Filter. 178,000 miles.
Went out one morn to use for the day and battery dead. Jumped off, went to local FoMoCo Dealer, Battery was several years old, so I replaced it with Motorcraft.
2 days later, dead battery again. Jumped off, went to favored local shop and alternator tested bad. Replaced.
4 days later, dead battery again. Jumped off, took to local shop and left it with them to go over thoroughly.
Shop Replaced GEM module. Still have problems.
Shop went through inspect of all fuses and fuse panels but all look fine. Did multiple draw test, all normal. Shop gave up after 3 months.
Took to Local FoMoCo Service Dept. After 2 months, they give up also.
Brought home, read and talked to many. Pulled factory radio. Still have draw.

I notice clicking under dash, feels most prominent in Relay 2 Battery Saver Relay. Pull Relay, clicking stops.
Have read that replacing this relay does not help, so for now just leaving out.

Any thoughts? Kid turns 16 in 6 weeks, getting desperate!

 

First, fuse panels and fuses are not the problem with a current draw.
Second none of the shops apparently tried to isolate to a circuit very well.
Here is what you can do to see the draw and when the draw is cleared.
Use a 12 volt lamp and its socket that will light from the draw.
Place it in series with the positive cable to the battery.
It should light showing the draw is present.
Remove the engine compartment light bulb and be sure the Glove box light is not on or they will light the test lamp.
All doors closed and wait about 30 minutes to begin testing.
Begin disconnecting the Alternator first. If the lamp goes out the Alternator diodes are leaking or the regulator is faulty.
If no, replace the connection and go on to the fuse boxes looking for a fuse removal that puts the light out.
Note that the PCM, radio and Gem will take a small amount of keep alive current but it is in the milliamps not amps in the range for draw, and is normal.
Your problem is not enough common sense and effort was used.
Good luck.

 

Thank you Bluegrass. Sounds like a good logical sequence to follow. I will work on it this week.

 

Alternator checked out perfect by local alternator/starter electric motor shop.Used Multimeter instead of light, hooked up in series on positive battery post & cable.
Multimeter set to 10 Amp DC.
Draw registered 0.17-0.18 with all fuses & relays in place.

Isolated to Fuse 15, a 5 Amp fuse that controls;

• Stop lamp switch (speed control, brake-shift interlock)
• GEM (I have replaced once already)
• Rear Anti-lock Brake System (RABS) module

Draw dropped to 0.01 when fuse was pulled and stayed there as all other fuses & relays re-installed. Draw went back to 0.17 when fuse 15 put back in.

Which one of these three items would you suspect and tackle first, or am I chasing a ghost and should look elsewhere??

 

I will assume all above pre-setup was done before testing so no expected draws was included.
By reporting draw as .170/.180 you mean 170 to 180 milliamps.
That is not a large draw to a battery in good condition so should not drain the fully charged battery to below cranking point in say 12 hours. Just an opinion.
Go on to those circuits and further isolate each function.
This is not a time to begin guessing but follow up the same procedure if you want the issue settled.
Of the three you list, two are modules and more likely suspect do to the low draw current seen.
Good luck.

 

Did you wait the required 30-40 minutes for the battery saver to time out before recording that current draw? If not, the reading is normal.

 

Pre Set Up Steps taken:

• Removed Alternator & took to local alternator/Starter/electric motor shop for full checkup. All good
• Fully Charged battery
• Re-Installed Alternator
• Hooked Up Battery
• Started truck
• Shut Truck Down
• Turned on headlights for 15-20 seconds to remove surface charge/static from system.
• Disconnected battery
• Waited 30-40 min for all systems to time out and go to sleep
• Hooked up test light between battery terminal & battery cable
• Began pulling relays and/or fuses 1 at a time and recorded draw
• after pulling #15 fuse and seeing 160-170ma drop in draw, began re-installing other relays/fuses to see if draw remained constant at 10ma.
• Draw remained at 10ma until #15 put back in when it returned to 170-180ma, removed #15 and returned to 10ma.

By the way, left #15 out for 33+ hours, vehicle still starting strong.

 

Procedural error.

You have to have the test light/meter installed BEFORE you wait for the timeout (unless you use a procedure that does not interrupt the circuit). Otherwise, you reset the timer when you break/re-make the circuit connection OR MAKE ANY OTHER CHANGES TO THE CIRCUIT [emphasis added].

F15 powers the GEM module which contains the timer electronics. Your observations under the flawed procedure are normal. Re-do the test using the correct procedure and do not re-insert any fuses without the subsequent wait timeout.

 

Replaced the Brake Shift Interlock part with a Dorman product. Reinstalled all fuses, panels, etc. Waited 3 days, all cranking and staying fully charged now. The removed factory part had noticeable 'slack' in mechanism and at least this far seems to have been the source of the heavy draw. Letting my kid drive it periodically now to see how it does before I let loose on the road for daily use. Kid get license in a month so, all good.

Thanks to Bluegrass & ProjectSHO89 for your willingness to opine during this process!! You were both very helpful!!