Jumping car incident

=========================================================

Now that is interesting, as aarcuda and I reiterated what the OP posted: that he had only shorted out the battery terminals through the clamps from the jumper wires. The current would follow the path of least resistance, that being the short through the cable clamps, not some *downstream* component that isn't in the short circuit.

How in the world, think about it, or even make a drawing with a pencil and a piece of paper, would a short =directly= across the battery terminals involve a fusible link elsewhere in the engine compartment?

This is revolutionary information. We are going to change ohm's law right here in this n/g.

I hope he dies under his own vehicle when it falls of it's jackstands. Hope springs eternal.

Lg

It takes out the link that was carrying current from the alternator to the battery. That link may also have powered other things. I am not familiar with the car and don't have a wiring diagram in front of me.

--scott

OK...let me think about this for a minute.

No, I can't agree, even though there is a connection, as in a parallel circuit connection, with the alternator, starter solenoid/motor, etc etc.

Here. I'll prove it to ya.

Take a flashlight battery, of any convenient size, but you'll probably have to arrange them in series ( +-+- ) to get a bulb to illuminate.

Now go ahead and wire that series battery to a bulb.

See the bulb glow.

Now, take another piece of wire of sufficient length to *short circuit* the battery pack across the ends of the battery pack.

This will simulate the exact problem the OP claims to have encountered.

What happens to the bulb?

a) It burns out for some unknown reason b) It DIMS because most of the current available from the battery pack is flowing through the short circuit, a.k.a. *the path of least resistance* c) it burns brighter d) nothing happens

The correct answer...is b

Now how can a fusible link that is not being given as much current as it normally gets, *burn out*? There is only one possibility I can think of.

The *Jump Kit* negative was attached to the engine block instead of the negative terminal of the battery itself. So the *path* back to battery neg terminal was through a fusible link. But this ISN'T what happened, according to OP.

What happened was a direct short across B+ and battery terminal negative.

Do the experiment.

Lg

Think alternator and a dead short to ground.

The older GM alternators were on the ignition circuits, same as the Jeeps I drive.

Mike

Lawrence Glickman wrote:

The power comes 'from' the alternator to the battery positive and from their directly to ground.....

Think harder....

Mike

Lawrence Glickman wrote:

Wrong. The car was *running* when it happened, meaning that the alternator was shorted. Assuming that the (+) battery clamp has a thick cable going to it for the starter and alternator only (the other accessories are powered by a different thinner cable) and the thick cable has a blown fuse link due to the alt being shorted, that might would explain the problem.

Cheers, Andrew

He shorted the alternator terminals for 1 second ( his words ) and he blew the fusible link from the alternator to the battery.

IF you do the experiment I just posted...you will see for yourself...that is highly unlikely.

Try it anyhow, and see if I am right or wrong. Just do it. I'll send ya the money for the D cells if you insist!

Lg

WAIT A MINUTE. I THINK YOU ARE RIGHT!

The alternator saw the voltage drop at the battery during the interval of the *short* and blew the link trying to compensate for the low voltage by putting out TOO MUCH CURRENT!

Give the man a cigar, while I go out to the back yard to hang myself from a local tree.

Lg

I GOT IT ;-|

Geezus, that took a bit of doing. You are completely correct. I'm going to have to find a winch somewhere to finish pulling my head out of my ass. WTF? I'm demented and senile at only 60?

Lg

No sense going to extremes, but I think a public apology to Mr. Chang is in order. Bob

I guess you already realize your gonna need to verify your charging circuitry is still working once you get all this sorted out. Just thought I'd mention it.

Some people that post to this group have a huge amount of technical knowledge but lack the practical application side to it. All that is needed is to work in a garage that has a few wreckers for several months and the practical knowledge learned during that period would be worth it's weight in gold. If the top of the OP's battery was not blown off the fusible links would be a good place to start. Lights work, fuel pump comes on, everything but the starter? There was good advice given in this thread, too bad it was drowned out by the noise.

Sorry I doubted your Oriental Wisdom Mr Cheng.

BTW, go light on the starch, and I want those shirts ready by Monday !

Well, I'd accept the apology if you had apologized to me. I think the "A" and the "E" are far enough away from each other to not chalk that up to being a typo. Even in your apology you're still being a punk.

Sorry for the typo CHANG. It was a typo. We're being a bit

*sensitive* today, are we? I understand. Christmas is coming up and you don't worship the baby Jesus. Well, life sucks and then you die.

As a footnote...I would have to see this to believe it. In theory it makes all the sense in the world, but I am not about to sacrifice my own alternator to find out.

IOW, there is some Lab Work that needs to be done before I put my head on the chopping block and hand you the axe. As I can understand how it is "possible" for the fusible link from the alternator to have blown...that is believable, but I would have to see it to believe it. The reason I say that is because I have to think alternators are current-regulated as well as voltage regulated.

If there isn't a current-regulation circuit ( other than the fusible link from the alternator ), then I find it hard if not impossible to believe that anybody's alternator could put out enough current at IDLE rpm's to blow out the circuit.

This is a show and tell that begs to be inspected with a real world test on a real vehicle.

"Maybe" you just did the test, but like I said, 1 second at idle rpm...I find it next to impossible to believe that the alternator could push that kind of current in that short amount of time to fry the alternator link.

Anyhow, CHANG, it was a typo, so go take your heart medicine and enjoy a cup to TEA.

Lg

Well, I haven't had a chance to check it yet either, I've pulled the battery and am charging it and I might get a chance tomorrow night to get some diagnostic time in. It was at idle but it was fast idle too, not just regular idle as the car was cold and the engine was just started, plus the alternator puts out more current when it's cold than when it's warm. So idle current isn't just the measly current we all think of when we think of idle current. My alternator, if I remember correctly, puts out 105 amps max. I wouldn't be surprised if the alternator fusible link is toast but it still doesn't explain why the starter ones blew but of course weirder things have happened.

I honestly don't think I'm being overly sensitive. Come on. You were wrong this whole time, defended yourself and had the audacity to attack me for what I was right about the whole time and even in your apology you still had to throw in another bigot comment. Now you're in the little man syndrome where you have to call me by my last name. If by "we're being sensitive" you mean "I'm being a jerk" then maybe I can agree with you on something.

I need to check on my car if not get my car back on the road, but at least, to settle this debate. Maybe you'll get your wish that the car will fall on me while I'm working on it.. I suppose you think that wasn't extreme.

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Mr. Chang.

There, HAPPY NOW?

Mr. Chang. BTW, I get aarcuda's handle mixed up all the time, what kind of a name is that? You're taking this too personaly. l make a

*joke* and you go off the deep end. Calm down.

We need to do an experiment, Mr. Chang. I can't accept, sight unseen, this *theory* that even at high Idle rpm, which is what, maybe 1200 rpm? that the link blew in 1 second due to an overcurrent surge. I say it is *possible,* but you know I and no one I know is going to sacrifice a perfectly good alternator or fusible link to find out.

And what would that have to do with the starter motor cable, Mr. Chang?

This isn't over yet. Not in my mind. And not in yours, evidently.

It is going to be: a) detach the cable from the alternator to the battery ( the one with the fisible link in it ) and read it with an ohm meter.

b) detach the cable from the B+ to the starter motor and read the resistance with an ohm meter.

c) check to see if you have any alternator output when the engine is running.

d) check the battery voltage with the vehicle turned off, and again with it running.

Somewhere in here a discovery will be made, and this can go down *in the books* as one mysterious techicality.

I hope you didn't find anything in this *offensive.* If you did, then I know a doctor you can see ( =my= doctor ).

Lg

I've never met many bigoted Jews. You're a rarity, Glickman.

Here's a picture of an aar 'cuda identical to the one I own, except mine doesn't have the little black spoilers on the lower front fenders.

(orange car, top of page)