Re-installing Battery - Sparks, Smoke Help

Discussion in '80-Series Tech' started by skii, Mar 21, 2010.

  1. skii

    skii

    Messages:
    90
    Location:
    Vermont
    Removed the battery and box this morning to work on a belt issue. I reinstall the box, ground wire, holding bar and battery. Hook up the + first and then hooking up the negative I get a spark, the lights go on and I sometimes get a bit of smoke. This can't be good, whats going on?
  2. lt1fire

    lt1fire

    Messages:
    13,110
    Location:
    Charlotte N.C.
    When there is smoke normally it means that the positive and negative are bridging somehow. Check those connections again.
  3. Ivan80

    Ivan80

    Messages:
    341
    Location:
    Omaha, NE.
    Assuming you have the battery polarity correct and you didn't create some sort of short when wrenching...If you have accessories on, like lights as you mentioned, it is normal to get a spark at the battery terminal when hooking up the battery. I imagine the smoke you speak of is from the spark?

    Turn off all the lights, remove the key from ignition, shut the door (so the door courtesy lights are not on) if you want absolutely no spark, pull the radio and the dash clock fuse and reconnect the battery.

    If you still get anything other than a very minor spark, you have created a short somewhere.
  4. skii

    skii

    Messages:
    90
    Location:
    Vermont
    I turned off the lights and after a brief spark all was well. First time I've done this so I was concerned.
  5. SBFJ60FIG

    SBFJ60FIG

    Messages:
    1,015
    Location:
    Chicago!
    Yeah no worries, a little spark will happen...when I re-hook up battery cables I do it quickly as I know there will be a small spark. And not that this really matters but at times I will blow on the area prior to hooking the cable up to clear any potentially explosive gases that may build up.

    This last part is probably totally not needed as I've hooked up many many batteries in my years of car, boat, etc repairs and I've never had a problem. But they do put blowers in boat engine compartments for a reason right?
  6. tlcruiser66

    tlcruiser66

    Messages:
    708
    Location:
    Western Wa.
    Sparks aren't normal unless you have a draw on the system, if your accessories were all off you may want to look into where that draw is coming from or you may find yourself stuck someday because of a dead battery.
  7. enterconnect

    enterconnect

    Messages:
    500
    Location:
    AZ
    I just replaced my HG and am having a similar problem. I connect the + battery cable first and then connected the negative side, the horn went off and there was spark, smoke, crackling, etc on the negative terminal. I quickly disconnected the negative and did some troubleshooting. I found that when the GREEN wire is connected to the + terminal, the terminal sparks and smokes when I connect the negative side. If I don't connect the green wire, there's no issue when connecting the negative. Without the GREEN wire connected to the + on the battery I tired to start the truck but I'm not getting spark. The coil was checked per FSM and is working fine. I'm getting power into the coil but nothing is coming out. I'm stuck and have no idea what could be wrong. I checked all of the connections and grounds and everything is in place. I do have a KARR alarm that was on the vehcile but am not sure if this might be causing the issue with the horn. Any help or troubleshhoting ideas would be greatly appreciated. The LC has been down since December and I'm so close to getting it back on the road.
  8. atomicshawn

    atomicshawn

    Messages:
    711
    Location:
    N. O town, UT
    I’m thinking you’re on the right track with the car alarm. I have soiled myself on many occasions because of those d*#mn alarms going off when connecting the battery… as if you’re not nervous enough after doing a big engine repair like a hg. Does the “green wire” your referring to look like part of the factory harness, or is it isolated? How does it attache to the battery. Pictures would help.
  9. B Legit

    B Legit

    Messages:
    478
    Location:
    Seattle
    a pretty common law in the electrical world is that your ground should be "First to make and last to break". I would also completely avoid making and breaking connections when there is any kind of draw on that system, that should be the only reason you see sparks unless you are shorted to ground somewhere in your system.
  10. enterconnect

    enterconnect

    Messages:
    500
    Location:
    AZ
    The harness looks factory to me. The alarm is not Toyota so I'm unsure how it's linked to the wiring harness. Attached are some pics. The GREEN wire also broke and was replaced. (all wires were replaced)



    IMG_1802.jpg IMG_1804.jpg
  11. Dave 2000

    Dave 2000 SILVER Star

    Messages:
    1,280
    Location:
    Spain
    Well a couple of things come to mind:

    Yes the alarm can cause the battery terminal to spark along with the central locking taking up it's lock/unlock position, even many ECU's need to 'power up' at connection.

    Next with the 'first to make and last to break' saying, I have used that saying before but have found the following:

    The battery connection will still spark regardless of which is connected first if there is a current draw, I often put the earth on last, many batteries have the positive nearest the wing or fender if you will, if the earth has been made first then it is possible for the spanner you are using to tighten the positive terminal to short against the now earthed bodywork and can blow a hole in it, at the very least you will have a ton of sparks and if the battery has just come off charge then it will be venting explosive gases and the results can be horrific.

    Connecting the other way around is a lot safer and if you touch the bodywork/engine metalwork no big deal assuming of course you do not short the battery terminals together or your car has a very old positive earth system. :whoops:


    regards

    Dave

  12. enterconnect

    enterconnect

    Messages:
    500
    Location:
    AZ
    I forgot to mention that when I checked the fuses under the dash, the CIG 15A, WIPER 20A, GUAGE 10A, AND ECU-IG 15A were all blown. I'm going to check all the connections on the wiring harness to verify that it was done correctly.
  13. atomicshawn

    atomicshawn

    Messages:
    711
    Location:
    N. O town, UT
    That "wire" is actually a fusable link which is designed to break if there is a short, but they can be fragile and can break from physical stress. I was hoping it was an add-on circuit, that would have made this much simpler.
    So that circuit is powers a lot of stuff; pretty much everything related to the MFI system and some lighting, so yeah, if that is disconnected it wont start. You were moving a lot of those circuits around when you had the head off, so there is a chance you got something pinched or chaffed.
  14. enterconnect

    enterconnect

    Messages:
    500
    Location:
    AZ
    I'll go thought the whole car and see what I find. I'll keep this updated. Thanks atomic for the info.
  15. skibob

    skibob

    Messages:
    136
    Location:
    Oregon City
    firs to break last to make is ABSOLUTELY BACKWARD when working with your car battery.
    Think of it this way, if you connect the pos after the neg, and your wrench touches a grounded metal part, you will get more than a little spark. If you really ground out, you can discharge the entire contents of your battery. That's a lot of juice. Your wrench may become very hot, may even weld to the body. You can end up with burns, the battery can explode under just the right/wrong conditions.
    Conversely, if you connect the positive first, then the neg terminal, you can touch whatever you want as many times as you want, since there is not a complete circuit, the worst that can happen is that you will scrape your knuckles.
  16. Dave 2000

    Dave 2000 SILVER Star

    Messages:
    1,280
    Location:
    Spain
    Come on skibob have you been skimming the posts again?

    Check out post #11, you could have saved yourself some ;) typing

    regards

    Dave
  17. enterconnect

    enterconnect

    Messages:
    500
    Location:
    AZ
    I go from + to -
  18. enterconnect

    enterconnect

    Messages:
    500
    Location:
    AZ
    I rechecked all of the connections and wiring. Off to Toyota it goes.
  19. atomicshawn

    atomicshawn

    Messages:
    711
    Location:
    N. O town, UT
    If you have to take it in, the dealer is often your best bet, but spendy. Too bad your not in northern Utah. Let us know what they find. I'm interested.
  20. enterconnect

    enterconnect

    Messages:
    500
    Location:
    AZ
    I'll post the outcome.

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