In this video we have a look at a Ford F-150 that has an issue with the battery dying overnight. Although I did not see the problem initially, allowing the vehicle to sit for hours paid off. -Enjoy!
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48 thoughts on “Ford f150: battery dies overnight”
  1. Avataaar/Circle Created with python_avatars Mark Guido says:

    I think you do fabulous work I think you're awesome with when it comes to that stuff you're a smart man I like watching you I enjoy it thank you for doing it for us

  2. Avataaar/Circle Created with python_avatars Mike Hudson says:

    I had a parasitic drain that two so-called auto electrical specialty shops diagnosed. One said bad ignition switch- installed new one and not fix it. The next one said bad radio amplifier- installed a radio and not fixed. It would drain over night and not start in the morning.

    My work around was installing a Optima Yellow Top start/deep draw battery. It would last the night, let me start the truck, and driving to work recharged the battery.

    3 years later my stater died and after installing a new starter the parasitic drain disappeared.

  3. Avataaar/Circle Created with python_avatars Not your Business says:

    Why's he going on the third alternator change.
    That the needed diagnoses.
    Many people keep changing them.
    Please figure out why the alternator's going bad.
    Or perhaps the draw is causing the alt to be overworked
    Ending in the bad alternator. ?
    Mine has random dead overnight. But it's as if a giant circuit breaker popped.
    Jump it shut it off and only a couple minutes and start right up like it wasn't ever low.
    Use once a day that will not happen two days dead battery.
    But not a little dead absolutely dead no dash no radio stations everything blanked out.

  4. Avataaar/Circle Created with python_avatars Gabe Ristick14 says:

    My truck has a dead battery but the air conditioner goes on is it the battery let me know

  5. Avataaar/Circle Created with python_avatars Pieter Naude says:

    Hi Eric .. sorry 3y later 😉 Some idea on why the current-draw started after a few hours. Semiconductors (stuff the Diodes are made from) tend to decrease their resistance as they warm up .. increasing the current flow. Conductor's do the opposite .. decrease current .. as they warm-up.

  6. Avataaar/Circle Created with python_avatars Chucker power says:

    You the man ! I had radio+ alternator causing draw!😮‍💨

  7. Avataaar/Circle Created with python_avatars Star Gazer says:

    God I hate watching grease monkeys try to troubleshoot electronic problems. Put your glowing lightbulb tester away. Sigh.

  8. Avataaar/Circle Created with python_avatars RICHARD lORD says:

    I had an overnight batter drain on A Chrysler cordoba once no-body could find the drain, disconnected the battery every night months later starter died, replaced it took the old starter apart and the armature had 4 copper wires broken and touching the housing. Never a battery drain again.

  9. Avataaar/Circle Created with python_avatars Fox Nakamori says:

    i am dealing with a similar issue with a 2006 ford f150, 4.2L v6 Gasoline, the truck can sit for weeks and be fine, then all of a sudden, out of nowhere the battery will die after it sits for 24 hours after being driven, battery always charges up just fine (yellowtop optima, less than a year old) and the truck can sit for weeks again at a time and start up just fine after sitting, i'm going to check to see if next time i have a no crank or flat battery if the alternator is warm, or when the charger is connected if the alt is warm, great video, and thanks for the insight as to the odd little gremlins that modern-ish vehicles have

  10. Avataaar/Circle Created with python_avatars GandalfTheLit says:

    I believe this may be my issue got an 04 f150 fx4, had to jump it today, i pulled the negative off the battery and she ran on the alt alone however it was very jumpy and it seems im losing power overnight. However this truck sat for a month with no one driving it and it started up perfectly but after driving home the next day it did this..

  11. Avataaar/Circle Created with python_avatars Larry Harris says:

    Thx for your assessment Eric, helped me out. I was chasing my tail. I have a 2003 F150 with same problem. Bought an alternator from a salvage yard. Had it checked out and amperage was good. Must of had a bad diode. Don't be cheap people, buy a new alternator!! So I just disconnected the alternator and BOOM, no more draw! Problem fixed. Thnx Eric, you gave me a direction to go in. Happy again😀

  12. Avataaar/Circle Created with python_avatars El Hungaro says:

    Cool 😎 👌 👍

  13. Avataaar/Circle Created with python_avatars Scott Horn says:

    That's a crazy intermittent alternator problem. The customer is not crazy and always right. I'm working on a 222 milliamp drain at the moment.

  14. Avataaar/Circle Created with python_avatars John Ryan says:

    Oh and also much love to him and his family.

  15. Avataaar/Circle Created with python_avatars John Ryan says:

    I think he is great! He always explains when he is doing something. I like it because there's no guessing.

  16. Avataaar/Circle Created with python_avatars Mechanicsville804 says:

    John 3:16
    For God so loved the world that he gave his only begotten Son that whosoever believeth in Him shall not perish but have everlasting life.

  17. Avataaar/Circle Created with python_avatars THE PIÑA CLAN 00 says:

    Best regard my friend awsome work.

  18. Avataaar/Circle Created with python_avatars Josh P says:

    Thanxs, great idea using the Infrared thermometer. Haven't seen anyone else utilize it. In my opinion the underdog takes the cake on this one.

  19. Avataaar/Circle Created with python_avatars Katalyst Kat + Apathetic Alyssa says:

    Thank you! I'll try this! I'm having the same exact issue. Replaced GEM module, alternator, battery, replaced the windshield (leaking).

    2001. I love my truck to death and when it works, it works well.

  20. Avataaar/Circle Created with python_avatars George Del Toro says:

    When you do a Good analysis ,you get good results. Alway enjoy your approach to a problem.

  21. Avataaar/Circle Created with python_avatars Shane Lomen says:

    I am a retired USN Electronics Tech., 20yrs; 12.5 years with Boeing Engineering Tech., 6.5 years as an Engineering tech. for GE Aviation. This video was very interesting and I have seen a similar problem in a Power inverter. The problem is most likely a leaky rectifier which when left alone after the system is turned off cools down. But, after sitting with the battery voltage sitting on one of its terminals slowly leaks current heats up then, pow, thermal runaway with max current draw. What do ya think?

  22. Avataaar/Circle Created with python_avatars Gregg Alexander says:

    I have a 1991 F150. Occasionally I find a dead battery in the morning. Yesterday, I had recharged battery all night. I took the cables of to recharge it. When I put the battery cables back on, I heard the usual quick 2 second pump sound. I have always assumed it was the fuel pump bringing gas to the injectors before I start the truck. This time it kept cycling! Even with truck completely off and no key in ignition. This is first time I heard this and it did it over and over. I disconnect cable to keep it from killing battery again. Any ideas?

  23. Avataaar/Circle Created with python_avatars Deadman says:

    It was informative, but unfortunately not the same issue I have. Both alt and battery were replaced and the same issue still happens.

  24. Avataaar/Circle Created with python_avatars Year 1226 says:

    Most likely the alternator or remote starter.

  25. Avataaar/Circle Created with python_avatars rubber MALLET says:

    sulfur batts sucks! 😋

  26. Avataaar/Circle Created with python_avatars Dan Schell says:

    Good job Eric these sneaky draws are difficult to catch I see this ford problem frequently When I suspect the alternator field is shorted on I use a screwdriver or wrench and touch the drive pulley if the wrench gets sucked on to the pulley like a magnet the regulator is on if there is no power is present on the red/green wire alternator is bad.

    I loved the current monitoring technique with the scope

  27. Avataaar/Circle Created with python_avatars scott McIntosh says:

    At Chevy they made us dismantle the alternator and only change the bad components !!!

  28. Avataaar/Circle Created with python_avatars Ed Lundquist says:

    I have been watching these videos. What a talented dude. And funny. I love the clean language. " what the thunder?" "Son of a monkey" "poop and laughter" keep up the good work! I just subscribed

  29. Avataaar/Circle Created with python_avatars IB Briley says:

    Diodes breaking down. Triggered by temp change.

  30. Avataaar/Circle Created with python_avatars lilflossin14 says:

    I have a 2005 f150, it was working fine until I turned it off now it wont crank or start. I can connect it to a car or charger and the battery will get up past 12v, won't start and I get a check gauges warning. Battery immediately starts draining unless I take off negative terminal then itll max out at 5.8v any ideas? I can take the key out once its turned to run position so maybe bad ignition switch but would that cause battery drain. Not sure how to test if battery keeps dying. Replace alternator and battery

  31. Avataaar/Circle Created with python_avatars Norm Esmonde says:

    Zener diode ?? My guess

  32. Avataaar/Circle Created with python_avatars Fred Hinck says:

    Alternator or just the regulator?? Many years in a Ford dealer doing this sort of tail chasing.

  33. Avataaar/Circle Created with python_avatars Darrin Fraleigh says:

    have a 2001 Excursion that is having the same issue. my question is was the alt charging while running/

  34. Avataaar/Circle Created with python_avatars John Williamson says:

    Glad this video , was here my 2002 f150 was doing the same thing, after watching this video after I got home I connected battery and let the truck sit and sure enough the alternator got hot , I replaced it and it is not doing that now. I was on a work trip so I was disconnecting the battery after I stopped to work or for the night so the truck would start later, funny that it was charging the battery while running. I am glad it was here and gave me something to look at.

  35. Avataaar/Circle Created with python_avatars MrOramato says:

    Why don’t they just have a hand crank that you turn to start it ?

  36. Avataaar/Circle Created with python_avatars Huggins PHIRI says:

    My 2010 F150 Battery drains overnight and I have resorted to disconnecting battery terminal when I get home. I have had several electricians look at it to no avail. What say you? 🤔

  37. Avataaar/Circle Created with python_avatars curlyq1269 says:

    Great video! So many mechanics just throw parts at problems instead of taking the time to troubleshoot the root cause! You're the man! Thank you for the detailed troubleshooting. A man after my own heart and detailed regiments!

  38. Avataaar/Circle Created with python_avatars Jon Ruehle says:

    My son's 5.4 F-150 is doing the same thing to him.

  39. Avataaar/Circle Created with python_avatars MacGyver 2 says:

    Its interesting it takes hours to start the drain. Curious why. Good problem solving.

  40. Avataaar/Circle Created with python_avatars Michael Nicholson says:

    Thanks Mr O !!! You could start a school with all your videos. Ever thought of selling them in packs like Can bus.. Wish i had the scope and the amp clamp (big jaws). I got a 2012 f150 with a over nite drain. Thanks again..

  41. Avataaar/Circle Created with python_avatars Druidor says:

    Had this on a few of my old cars diode pack failures