2001 F150 4x4 Supercrew V8 4.6L

I seem to be having a problem with my battery staying charged. Battery seems to go dead overnight (most times!) and it will start with a boost.
I have had the truck into two different shops over the last two months and $5000+ later I still have no answers for my battery/electrical problem....
If the trucks sits for more than a day it seems it will not start unless boosted.
Most times I have this problem however every once and a while I get lucky and it will just start.
Last mechanic was ford dearlership and they have replaced:
GEM, smart junction box, Module:multi Function, Fuse Box Assembly and a relay, they took out the remote starter on one visit and put it back in on second visit to them since I still had same problem. The battery is new (connectors and post both cleaned) they tested it and it was fine, they tested the alternator and starter and they were fine. Their doesn't appear to be any water intrusion either.
I am at wits end and BROKE paying these guys who don't seem to know anything and just keep replacing parts......
Please does anybody have an answer for what's is going on?
Thanks, Kevin

 

I know you said the battery was new, but remove the negative terminal one night and leave it disconnected. The longer the better, reconnect a day later to verify it will have the energy to start the truck. This should prove that the battery is not the problem. If you have any after market equipment (radio,sub) disconnect them for a day, make sure you get the keep alive memory for the radio also. Read the sticky in the electrical section on the stuck on door light, could have something to do with it.

 

Yes battery is New, I replaced it on the start of this problem two months ago when my old battery went dead a few times, the new one lasted a week afterwards and was dead and since I have been boosting it when it hasn't been in the shop that is....lol
I have read the post on the sticky door switch as well with the underhood light (I don't have) and the one about the glove box light....I have read through many of the posts and I do not have any aftermarket stuff on the truck. I have even made sure the radio is turned off, and the heater is off before turning off the truck at night. I also have checked to make sure all interior lights are off before leaving the truck in the driveway.

I will boost the truck, give it a good run and when I return I will try what you suggested and report tomorrow. Thanks.

 

sounds like you have the easy stuff covered, you could have a bad battery even though its new, long shot but maybe. Put a real voltmeter on the engine with it running, should be 13.5 volts, need to know if its under or overcharging.

 

OK Had the Ground off the battery all night before I put it back on I tested it with the meter and got 12.4, with connecting the ground back on before start I got 12.32 upon starting the truck it went to 14.95.

I also tested it with my battery & charging sytem tester (Cheap thing that plugs into cigarette lighter - three lights on it) The battery test read good, and the Charging System system test read good.

 

you need to test for draw on the battery.

leave the battery connected and check voltage every hour after shutting down. after about 40 minutes of shutting down my battery climbs to 12.6v and hold steady for several days.

 

Well up to 10pm last night it was 12.6 and this morning 11am it is at 12.3

 

As of 2pm it went down to 12.06, I did try to start it and surprisingly it did start.