12 replies to this topic

[kingbenvolio]

Hey there! I am running an 1981 Austin Morris, and i have a simple question!
A couple of days ago my boot was filled with smoke and the plastic covering on my Earth cable from the battery had melted!
I have checked and found what was shorting the battery; (pinched by the clutch strangely!) And that is now repaired, as is the Earth cable!
But my question is, do i need to buy a new battery? As i am paranoid about running the car too much after this, dont want the battery to give up on me!
I did a 20 mile round trip in it yesterday and it all seemed fine..! Just want some reasurance, or some advice on a new battery!
Cheers all!

[tiger99]

Theoretically you may have reduced the life of the battery, although it is impossible to tell, but it would be pointless to change it while it still works. If you don't get starting problems in cold weather, the battery is good enough.

Batteries can overheat and explode if heavily shorted when fully charged, but as that did not happen, I would be inclined to be optimistic.

By the way, this happened to me once. Where the battery cable bridges the gap between floor and front subframe one of its fixing clips, the one with the white plastic spacer, was missing, so it moved sideways and shorted to the hot exhaust every time I accelerated, promptly causing the engine and everything else to cut out. I seem to recall that the battery was ok for quite a long time after that incident.

[kingbenvolio]

Ah thats good news! Thankyou!
Nice to hear from someone that had a similar situation :')
I'll just keep running my battery as it is now; my father in law gave me one from his Picasso.. Backup aye

[mini13]

give the battery a charge and see what the output voltage is,

what can happen is the plates in the battery over heat and distort, if they touch that cell goes short circuit and the total voltage will drop...

[bmcecosse]

If it did a 20 mile run - it's fine. It could have exploded -you were lucky to get away with it so lightly.

[tiger99]

I don't think any cells have shorted. A voltmeter is the ultimate test (off load, engine not running, should be absolute minimum of 12.6V, more likely 13.8V if freshly charged, but one dud cell will mean maximum is 11.5V) , but if one cell had shorted, the alternator charging the remaining 5 cells to 14.4V, as it should, would mean that they were all grossly over-charged and would be gassing furiously.

Modern batteries are more robust than they used to be.

[Al n Gav]

Hey there! I am running an 1981 Austin Morris, and i have a simple question!
A couple of days ago my boot was filled with smoke and the plastic covering on my Earth cable from the battery had melted!
I have checked and found what was shorting the battery; (pinched by the clutch strangely!) And that is now repaired, as is the Earth cable!
But my question is, do i need to buy a new battery? As i am paranoid about running the car too much after this, dont want the battery to give up on me!
I did a 20 mile round trip in it yesterday and it all seemed fine..! Just want some reasurance, or some advice on a new battery!
Cheers all!

I think this just happened to me! Whirring noise from engine, melted earth cable in the boot and smoke from the clutch cover!!!!!!
What do you mean by "pinched by clutch" and how do I fix it???
Thanks

[kingbenvolio]

Reliving an old haunt!

Basically as the clutch moved, it was making contact with the main live cable, that connects from the battery. I would suggest following the cable from where it leaves the battery, (checking every single inch) Right up to where it meets the Solenoid.
It might have been possible that it has simply chaffed away the plastic coating and causing it to short out on the body somewhere.
Also check incase something metal hasn't made contact with the battery terminal in the boot itself, it may have shorted that way!
Ummm, im sure someone else will be able to give a few suggestions!
Just make sure to change the Earth cable!


Smoke from clutch cover.. Missed that part.. You'll be better off asking a question on the forum itself that hashing up my old crap!

Edited by kingbenvolio, 05 June 2012 - 09:52 PM.

[tiger99]

Surely a whirring noise from the engine is caused because the starter is running when it should not be, due to a faulty solenoid, or wiring short? And yes, if it persists, it will overheat the battery cables, which are only rated at 300 amps or so for a very short time. The starter may have suffered an internal failure and caused smoke to enter the flywheel housing. If the engine is spinning the starter, very fast due to the gear ratio, the current involved may be very high indeed, as the starter will also function as a crude dynamo.

[Al n Gav]

Many thanks for the replies pretty much what I thought. The short actually melted the Pos terminal !!

[RobWill116]

This happened to me recently too, the live slipped out the bracket and melted on the exhaust link pipe. I can clearly see the damaged section of the live cable, it is just a case of cutting this section out and adding in a new piece of cable or is a new live cable in order?

[tiger99]

Neither, you will be delighted to hear. Changing the entire cable is a right nuisance and moderately expensive, while joining in a new section is basically impossible. How would you join it, bearing in mind it needs to be insulated, and carry upwards of 300 amps for starting?

All you usually need to do, provided no more than a few of the wire strands have broken, is to fix the cable properly, so it can't contact the exhaust, and wrap the damaged area thoroughly with self-amalgamating tape, readily available from Maplins. Trim off any distorted and bulging parts of the old insulation first, and as you wrap the tape, stretch it well, so it will remain tight.

[RobWill116]

Neither, you will be delighted to hear. Changing the entire cable is a right nuisance and moderately expensive, while joining in a new section is basically impossible. How would you join it, bearing in mind it needs to be insulated, and carry upwards of 300 amps for starting?

All you usually need to do, provided no more than a few of the wire strands have broken, is to fix the cable properly, so it can't contact the exhaust, and wrap the damaged area thoroughly with self-amalgamating tape, readily available from Maplins. Trim off any distorted and bulging parts of the old insulation first, and as you wrap the tape, stretch it well, so it will remain tight.

Ill keep that in mind if it evrr happens again, I went to my local mini specialist in giltbrook (surf blue) and got a second hand live cable in very good condition. So I have replace the whole cable, wasn't too much of a hassle. And it didn't cost much!