Same car problem again

Discussion in 'Off Topic' started by buster40c, Oct 2, 2016.

  1. buster40c

    buster40c Well-Known Member

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    Again my car is dead electrical just like the battery is disconnected. The ATO mini fuses that have power only have around 6 volts. The power wire at the ignition switch also only 6v. The main 60A battery fuses show around 12v. The last time this happened I replaced two battery fuses and two relays and then the car was up and running. This time that didn't help. I checked and do have good ground to engine block from battery.
    Other than hearing the PWR/TRN relay clicking nothing electrical works. I disconnected the negative cable for a minute but that didn't help reset anything either.
    Why only 6V where it should be 12V? Is this due to a faulty ECM/BCM? Funny that the car ran okay for about two weeks but now have same problem and it isn't clearing itself this time.
     
  2. Blkhawk73

    Blkhawk73 Member

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    Had you checked the battery itself? do you have or have access to one of the smart chargers? They can often diagnose a battery issue.
     

  3. buster40c

    buster40c Well-Known Member

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    I checked the battery with a volt meter and it showed over 12v. I know that isn't really telling the battery is good because the amperage could be insufficient.
    I had put a charger on it in boost start position and it acted like something was wrong. The battery charger did show the charge was good. Maybe I need take the battery out and have it checked? Maybe just swap the battery with the battery in my truck?
     
  4. Tommycourt

    Tommycourt Tommycourt

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    Buster,

    You might want to check to see if you have something that is grounding out somewhere. It doesn't take much for a small wire, even a 14 gauge to ground where it might be rubbing, say against the frame. It is very frustrating and sometimes very time consuming. When I built my model A speedster I had a 10 gauge wire that was rubbing very slightly against the frame. It looked good but when upon closer inspection, I found the wire to have a very slight part of it where the wire was exposed. Also not knowing the year and make of the car, I would start from the battery and using an amp meter check the car when running. If it's a 12 volt, you should be charging @13.5 volts. Clean the terminals real well using baking soda and water. From there, then you start checking on where the ground wire runs. Chilton manuals are fine but they don't really apply to a certain car, they generalize. You can buy a manual for about $20.00 that will cover your car specifically and it will give you a schematic on the wiring diagram. Also check for loose terminals on all connections. If they are loose or suspect, you can change the end of the wire or even run a splice. Having ground testing tool can provide a lot of info. Head down to your local Checkers, NAPA, AutoZone and they can provide you with a book and a ground testing tool. You can buy one for about $8.00 and it will tell you if you have something grounded or not. The light will come on if the wire is hot. Another possibility is Google your year of car, model, and then you can bring up a print out of your wiring system. Another way is to go on YouTube and do the same. Hope some of this helps.

    Tommy
     
  5. buster40c

    buster40c Well-Known Member

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    When I put the battery charger on emergency start 50 amp and connected to battery the charger quickly goes nuts like it has a short. The meter jumps up then down to zero then repeat the same. This is with battery ground hooked up or not so that should be telling it is something in the battery not the car causing the seeming short.
     
  6. VThillman

    VThillman Active Member

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    Tommy is the expert here. I'll just point out that a wet cell battery at full charge should show 2.3 Volts per cell. That's 2.3 X 6 = 13.8 Volts. Back when I was paying attention, the regulated/converted charge from the alternator was delivered at about 14.5 volts.

    A simple check - that doesn't fix any problem - involves giving the battery a full charge from a battery charger, then checking the voltage. Let the car set for a few hours, then check the voltage at the battery again. If it is down much at all, there is a ground somewhere. Like I say, who knows where?
     
  7. buster40c

    buster40c Well-Known Member

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    Lights Camera Action!
    I found the problem. Removed the battery and had it load tested and it checked ok. Before fastening the battery cables I checked for continuity on the cables to the connectors and the positive cable to the fuse box I had trouble getting continuity. I had it when probed the cable ends but mostly not at the eyelet that attaches the cable to the positive battery clamp. Before I had checked the positive cable to engine but I hadn't checked this fuse block cable. I thought well how about that? It is the cable that feeds power to the fuse block. I sanded the eyelet surface till it had shining metal. I installed the battery terminals and SHA ZAM I had power to everything.
    So all it cost me was a lot of aggravation and time.
     
  8. Tommycourt

    Tommycourt Tommycourt

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    Buster,
    It's hard to tell what the problem is without knowing what type of car, year, model and make. Take the battery out of the car, put it on a trickle charge and let it charge overnight. It should read about 12.3 volts. Check it an hour later and see if the battery is still @12.3 volts. It might be a hair higher and that doesn't hurt BUT if it drops below 12.0, then the battery is bad.
    If the battery stays up, then you have to run a test light, starting at the pos/neg wires, making sure they are clean, install the battery and start looking for shorts. The test light will tell you where you are shorting out. The car does not need to be running, you just need the ignition switch on. Now I am assuming it's a later model car (1990 or newer). When the car is running, like Bob said it should be running 13.5-14.5. If it doesn't, then more than likely it's the alternator or voltage regulator that is bad. The voltage regulator is mounted inside the alternator so you will have to replace the alternator. If it shows that the voltage regulator is good, and again depending on the car, the ECU is indicating that something else is wrong. Then head to a NAPA or O'Reilly's store and they can run the diagnostics on it and they normally don't charge for that. It will spit out a code, which they can go to their books and give you and indication of what is wrong. They are not always right BUT at least they can give you a direction on what to look for. You have to start with the basics and work your way up from there. With very limited information, I am guessing that you have a short or possibly the ECU is not functioning correctly. There is a way to by-pass the ECU however it will take an experienced mechanic to trouble shoot it for you. The ECU is the heart of the operation on later model cars and can give you an insurmountable amount of info. On some older models, you can turn the key off and on 3 times and the light will blink so many times on the dash. If it does, then count the number of times it blinks and the NAPA or whomever can decipher some of the problems. Without knowing the type of car though, we are just shooting in the dark. I'm sorry but that's all the info I can give you with the limited amount of info you have supplied.

    Tommy
     
  9. Tommycourt

    Tommycourt Tommycourt

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    Looks like I made my post just a little late. I was posting and after I just got done, I saw your post. Glad you got it worked out.
    I wasted my time for nothing, but that's ok.

    Tommy
     
  10. buster40c

    buster40c Well-Known Member

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    Well I thank you for taking the time to help me. It is a 2006 Impala 3.9 LT with all the computer crap. Thanks for the effort Tommy and others.
    I hate to think about these new cars that drive for you, back up for you, and brake for you after they have many years on them. Now that could be an expensive to fix nightmare. I don't even like ABS let alone all this new drive for you so you can text.
    I don't know what others think but I sure don't trust a vehicle that can apply the brakes and control the steering. I can just imagine what might happen when an internal brain sees a sign for free parking. LOL It just might be a problem.
    PS: Tommy from what I heard keeping your fingers moving keeps stiffness away. So see you didn't type away for nothing.
     
    Last edited: Oct 2, 2016
  11. MagBlackhawk

    MagBlackhawk Patriot

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    Some grease on the terminals will keep corrosion from forming. ;)
     
  12. Tommycourt

    Tommycourt Tommycourt

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    Buster,

    My fingers are so nimble now that I can go shoot twice this week- after the swelling goes down!:cryinglaugh:

    Glad you finally got it. Many times little things like short circuits or relays and fuses can really give you a head ache. Now you know what to look for the next time it happen- and I hope it don't.

    Tommy
     
  13. spikedriver

    spikedriver Active Member

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    I hear you about the new car technology. My 2005 Buick started to apply the anti lock brakes at random times, for no reason whatsoever. It was annoying the first time, going 25 mph. It was terrifying the second time doing 75mph on the freeway in traffic. I took in to the shop and he said the slip sensor in one of the wheels went bad, but couldn't tell which one. I said how much to replace all 4? 800 bucks...I yanked the anti lock fuse. Voila, problem solved. $!#& sensors anyway...
     
  14. buster40c

    buster40c Well-Known Member

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    ^^ So all I have to do to disable the ABS is pull the fuse? That will allow me to brake as hard as I see fit? I really don't like ABS because it is like the old time drum brakes that would fade when applied real hard. I had a Chrysler 300 that the brakes like to scared the crap out of me. If the cars hadn't started moving when they did I would have surely hit them. ABS sucks IMO.
    If a driver knows how to load down the front end then the brakes can be applied very hard without a lock up.
     
    Last edited: Oct 5, 2016
  15. VThillman

    VThillman Active Member

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    If the ABS functions like it's claimed to, it will stop you exactly as well as an expert, extremely conditions-aware driver. So... what are you telling us, Buster?

    ;)
     
  16. buster40c

    buster40c Well-Known Member

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    My experience with ABS brakes has shown me first hand ABS brakes don't even measure up to what the makers claim. That's what I am saying.
     
  17. VThillman

    VThillman Active Member

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    Hah. Well, that's what I figured you were saying, Buster. :D

    My experience is that they usually work OK for the first year or two - if you always drive on clean pavement. Then the sensors get dirty or deteriorate, and things get iffy. They can be 'entertaining' in snow, too.
     
  18. spikedriver

    spikedriver Active Member

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    If you yank that fuse, the guage cluster will light up like a Christmas tree, but the ABS will be dead. It will probably take the traction control out with it.
     
  19. buster40c

    buster40c Well-Known Member

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    So in other words it wouldn't be a good idea to pull the fuse. The ECM would probably go nuts.
     
  20. spikedriver

    spikedriver Active Member

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    No it just make your ABS and traction control lights stay on all the time along with the "service vehicle soon" light. My Buick has a heads up display that now says "check gages" next to the speed. I just ignore all that but I know it drives some people nuts.