Come along with Eric O. at the SMA shop as we revisit the 2005 Ford Explorer that we diagnosed and repaired only to find that the new alternator could not meet the electrical demands of the vehicle! Let's see if this other "new" alternator works any better.
Part 1 :
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46 thoughts on “Charging system problem – voltage drops – the follow up”
  1. Avataaar/Circle Created with python_avatars H Heinssen says:

    Great Video as always. I have to say, since I found you’re channel, you got me inspired to start fixing things around the house/shop etc. No much to fix on the Truck though. It’s a Tundra. I started out with my dad, on general maintenance, and wrenching in 66. He taught me right, and I’m thankful. To this day I respect all my machines. I take care of them and they take care of me. Keep the videos coming.

  2. Avataaar/Circle Created with python_avatars bigbusa spanish says:

    I'm running 2 batteries on a 97 chevy 3500 an batteries draining as I drive an shuts off vehicle, with 2 new batteries an new alternator thinking pcm

  3. Avataaar/Circle Created with python_avatars patrick skaggs says:

    Eric you taught me a good lesson. I had that same problem. Win i had to walk home i was pissed off . I do not buy remand parts only new parts. I have not had a problem yet with a new part. But i do run test on the new parts now. I dont like walking

  4. Avataaar/Circle Created with python_avatars MPLS Car Sales says:

    I have 2013 Cadillac ATS 3.6 AWD premium battery light on,does the BMS Fuses control the output of the Alternator there like 6 of them ? It’s one of those so called smart charging systems

  5. Avataaar/Circle Created with python_avatars Johnathan says:

    well your not going to like that I'm about to say but it needs to be said. so a few things I had notice the first thing is that when you were talking about the amps and showing your OBD scanner you had the setting on VOLTS not AMPS after you moved it the second time over to the battery area and you change the settings on the OBD you had then put it on the right setting then and it had and (A) = AMPS next to the numbers and not a (V) = (VOLTS). The other thing you had said at the end is about the clamp being on the wire and said about the flow of power sorry to say but it doesn't know witch way the flow is going you can put the clam either way and you will get the same reading from it. I thought you might want to know that so you can re-edit that or pull that one so you don't look like you don't know what you are talking about or worse mislead your viewers with the wrong info.. I'm not trying to be a smart ass over it I'm just letting you know from what i seen and heard. Well have a good one. Bye
    From a viewer,
    Johnathan Townsend

  6. Avataaar/Circle Created with python_avatars RetiredGuy Adventures says:

    I know this is an older video, but when you say Advance sent you a "new" alternator do you mean they sent a new Carquest alternator?

  7. Avataaar/Circle Created with python_avatars Shade Tree Mech says:

    Yes, Eric I definately learn from your vedeos.

  8. Avataaar/Circle Created with python_avatars FAUSTO GONZALEZ says:

    Great job Eric, I like the way you emphasized the current flow amount and the direction to the different loads. Especially at Idle w/ no loads and high loads as well as high RPMS w/ full loads and pointing out the fact, you better have positive current flowing into Battery VERY IMPORTANT, also especially High Loads at Idle, if Alternator not operating properly, it will not put out enough current to supply the high loads while maintaining a positive current flow into Battery !! Awesome , thanks so much , I'm big fan of your videos – keep up the great work !!

  9. Avataaar/Circle Created with python_avatars Donny Lansing says:

    I have a question, maybe a dumb one. Could you have I noticed there was a problem with the remanufactured alternator by just looking at battery voltage with the truck running with a load. Or do you have to dive in and look at amperage?

  10. Avataaar/Circle Created with python_avatars Shane Harrison says:

    Full baskets better than an empty one good explanation excellent analogy remaned used to be better than new no it seems no where near

  11. Avataaar/Circle Created with python_avatars William Whitehead says:

    Does the cub CPU cover now much the battery gets back in the charge or is that not on that model I know that 07's have a computer regulating the regulator for the alternator to battery?

  12. Avataaar/Circle Created with python_avatars Justin Southworth says:

    21 amps?!? Sir, that says .21 volts

  13. Avataaar/Circle Created with python_avatars charlienws says:

    What was the problem and the fix at the end. I didn't get it

  14. Avataaar/Circle Created with python_avatars James Washer says:

    Eric, just a simple question. Are we confident the engine is idling at the correct rpm?

  15. Avataaar/Circle Created with python_avatars Pinkie Love says:

    my car never goes past 13.7 volts ever ,, most driving around town or high way it does 13.4 13.5 if i turn something on it goes down then right back up to steady voltage…. but at idle sometimes voltage goes to 13.0 12.9 if i turn my lights on while idle it goes down then up to idle voltage of 13.0 .. these are all readings are from my obd 2 maestro for my aftermarket radio gauges could be off .2 volts … every car is different in there requirements… but video gives you great insight into what to look for… great video

  16. Avataaar/Circle Created with python_avatars Adam Sears says:

    I know this is almost 3 years old but it helped me figure out why every 2 weeks my Battery is near dead. This Alternator isn't putting out enough amps to keep up with my 89 Ford F150 inline 6. Tomorrow shopping for a new Alternator.

  17. Avataaar/Circle Created with python_avatars Dano C. says:

    Great explanation. Not too often you'd have the A/C on high (maybe heat) w/ wipers and defrost, but still we got the point. Thanks Mr. O.

  18. Avataaar/Circle Created with python_avatars Itwas AfakenameLol says:

    got a issue I usually run 14.4-14.7 voltage but when its warm out and car hits temp it drops to 13.9 at .1 at a time till it hits 13.9 then after a min or two it goes back to 14.4-14.7 at .1-.2 at a time .usually wont do it when its cold out is this normal or something I should ve concerned about im not running radio,heat or ac

  19. Avataaar/Circle Created with python_avatars Mark Pedzinski says:

    God damn these crackheaded crack supplying ads! Fuck you!

  20. Avataaar/Circle Created with python_avatars Howard Iko says:

    Automotive new better idea. ECM charge controll. Sure to over voltage or under charge the battery with Pulse with modulation.

  21. Avataaar/Circle Created with python_avatars fireeater 420 says:

    Lol ya N.E.W. never ever works.

  22. Avataaar/Circle Created with python_avatars rafael valenzuela says:

    Eric, I want to see the first part of this follow-up can you tell me wich it is? thank you

  23. Avataaar/Circle Created with python_avatars Ronnie Rawson says:

    Thank you so much this video was the best I learned so much, Thank god I caught this on my Jeep, Would have been a cold walk in snow, Still alive! Working on getting a new oem and not remaned one.

  24. Avataaar/Circle Created with python_avatars Michael Pistilli says:

    I hear a charging alt, didnt hear that noise with the second alt, its charging a low battery and than the load. I understand that an alt will maintain a charged battery but charging a low batt can kill the alt, I always test and charge the batt before alt testing The low or failed batt will affect the charging voltage with loads

  25. Avataaar/Circle Created with python_avatars BellaRocko says:

    This is the car channel from which I learn the most! Eric is an excellent technician and a great teacher! His interactions with Mrs. O and funny comments are entertaining as well. Thank You, Eric!

  26. Avataaar/Circle Created with python_avatars David Sprocket says:

    Very Good. I wonder if you were to check other alternators from the same supplier and see if the output specification sheets are all the same?! The stators of re-man alternators could be of higher and lower outputs and I wonder if the alternator is actually tested as claimed? You went that extra 1000 miles to make certain it was the best it could possible be.
    A true professional!

  27. Avataaar/Circle Created with python_avatars Jim Storm says:

    Would that tell you the same thing clamping the the large cable of the negative side of the battery????? Because each amp using device has it's own ground ?

  28. Avataaar/Circle Created with python_avatars Rick Higson says:

    Nice job!

  29. Avataaar/Circle Created with python_avatars Whirl Wind says:

    I would like to add a comment . I was in a mild accident with a 2000 body style f250, a car crossed my path . Two things happened over time. #1 my radio began to work intermittently and the jolt of the accident and the heaviness of the radio applied pressure to the faceplate and thus the radio began to short out. But here is what happened next.
    Driving down the highway at night. Lights began to dim, battery discharged and engine started running bad and I had to cross 3 lanes to get to the shoulder in heavy traffic no lights.
    Being mechanically inclined I took a cab to the part store and bought an alternator. I replaced mine roadside and the truck started and IO made it 1 mile and it happened again.
    From there I had it towed to a shop.
    Here is where Ford voodoo technology baffled me. THE INSTRUMENT CLUSTER VOLTMETER CONTROLS THE ALTERNATOR OUTPUT AND i NEEDED A 500$ INSTRUMENT CLUSTER FROM FORD TO SOLVE THE ISSUE.. It seems the accident also stressed the instrument cluster and over time it failed also. This failure mimics a bad alternator .

  30. Avataaar/Circle Created with python_avatars Michael Donavon says:

    Eric.  To see if I am on the same page as you are, let me posit this:  In reality the current flow is from the  chassis ground – through the alternator (via the diodes, etc.) then through RL, the load, then, being attracted to the Positive terminal of the battery.  We saw what the alternator was providing, current wise, then we turned to the positive battery post (looking at the amp clamp on)  to see "what current was left" from what the alternator was giving us. (based on the load requirements.)   I= E/R.  Right?   Is what I'm saying correct?   Can we say that from the Alternator output, thru the load, then on to the positive term of the batt is mearly a D.C. Series circuit?   I think it is.  Then from the positive term to everywhere else, we have a major parallel circuit.   What do you think?  Many thanks, N-6395T   B-6370

  31. Avataaar/Circle Created with python_avatars Cragified says:

    Now imagine how bad the issue is going to get with remans with electric AC compressors, electric steering, etc. on modern cars.

  32. Avataaar/Circle Created with python_avatars Mike Chiodetti says:

    Ya, I'm guilty as a lot of others of not checking for voltage drops at every alternator change, however I did check many of them, using our Snap-on battery, alt and starter tester. Caught a lot of problems that way! GREAT VIDEO FOR DIAGNOSTICS, keep them coming!

  33. Avataaar/Circle Created with python_avatars Gary Kniss says:

    That red 94 Bonneville (11.33) doesn't look like a NY car. There's no rust holes in the sail-panels.

  34. Avataaar/Circle Created with python_avatars Duncan Mac says:

    Absolutely perfect explanation on the workings of the system. Thanks for the video.

  35. Avataaar/Circle Created with python_avatars n8pu says:

    Even to the non-mechanic ear, when you turned the load on the new alternator, you could hear the out put increase with the belt noise and the engine slow some under that load, I couldn't hear that same sound with the reman one.

  36. Avataaar/Circle Created with python_avatars Ricardo Martinez says:

    Great video Eric, do you know if this is a computer controlled alternator?

  37. Avataaar/Circle Created with python_avatars Christopher Andrews says:

    I always LEARN, every time with these videos. Excellent job! Thank you!

  38. Avataaar/Circle Created with python_avatars Steve C says:

    I always buy OE new alternators. I have had so much similar trouble with Reman out there and it seems like the parts counter just wants to fight with do it yourself folks like me because they think we are the idiots meanwhile it's a quality issue.

  39. Avataaar/Circle Created with python_avatars Michael Kuzemko says:

    I had a question Mr. O. I'm a little confused. Maybe I missed something. In your previous video to this, you said there was a deficit of about 17 amps at full load. In this video you said that roughly 2.5 amps were replenishing the battery. It looked like you hooked the amp clamp around the same junction box wire. Did you hook the amp clamp around a different wire as compared to the one you used in the first video?

  40. Avataaar/Circle Created with python_avatars Yep Blaze says:

    The new one sure sings a lot. Noisy But I guess electrons are just that way the old one didn't sound like that. Wheeeeeeeeee

  41. Avataaar/Circle Created with python_avatars Fender Bender says:

    You know a lot of people can work and even talk at the same time.

  42. Avataaar/Circle Created with python_avatars SteveB says:

    Amazing video as always! I'm a little confused about one thing – in part 1, amp testing from the battery showed about a +12 amp deficit (being made up for by the battery itself not the alternator) and the amps went negative when revving up. In this video, testing of the good alternator showed +3 amps coming off the battery. Would those 3 amps be a deficit as well, or was the clamp just reversed here, or am I misunderstanding? Thanks!

  43. Avataaar/Circle Created with python_avatars Steve Turk says:

    Another great video! Thanks Mr. O ! 👍👍

  44. Avataaar/Circle Created with python_avatars Richard 1 says:

    This video is the best video I have ever seen on the Charging Circuit. Great Job Eric.

  45. Avataaar/Circle Created with python_avatars Isshman Garcia says:

    EXCELLENT VIDEO Eric O. Ive Learned a bunch of much needed info from this vid at a time when Im dealing with a similar problem.

  46. Avataaar/Circle Created with python_avatars Justin Ballard says:

    I was doing my annual charging system check on my silverado and with all loads on my voltage was at 12.8 I did my voltage drops and all was fine I replaced the alternator and it now charges 14.5 with all loads on. I would not be happy with that ford's alternator at all.

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